Adolf Hitler (20 April 1889 – 30 April 1945) was an Austrian-born German politician and the leader of the National Socialist German Workers Party (German: Nationalsozialistische Deutsche Arbeiterpartei, abbreviated NSDAP), commonly known as the Nazi Party. He was Chancellor of Germany from 1933 to 1945 and, after 1934, also head of state as Führer und Reichskanzler, ruling the country as an absolute dictator of Germany.

A decorated veteran of World War I, Hitler joined the precursor of the Nazi Party (DAP) in 1919 and became leader of NSDAP in 1921. He attempted a failed coup called the Beer Hall Putsch in Munich in 1923, for which he was imprisoned. Following his imprisonment, in which he wrote his book, Mein Kampf, he gained support by promoting German nationalism, anti-semitism, anti-capitalism, and anti-communism with charismatic oratory and propaganda. He was appointed chancellor in 1933, and quickly transformed the Weimar Republic into the Third Reich, a single-party dictatorship based on the totalitarian and autocratic ideals of national socialism. Hitler ultimately wanted to establish a New Order of absolute Nazi German hegemony in Europe. To achieve this, he pursued a foreign policy with the declared goal of seizing Lebensraum ("living space") for the Aryan people; directing the resources of the state towards this goal. This included the rearmament of Germany, which culminated in 1939 when the Wehrmacht invaded Poland. In response, the United Kingdom and France declared war against Germany, leading to the outbreak of World War II in Europe. Within three years, Germany and the Axis powers had occupied most of Europe, and most of Northern Africa, East and Southeast Asia and the Pacific Ocean. However, with the reversal of the Nazi invasion of the Soviet Union, the Allies gained the upper hand from 1942 onwards. By 1945, Allied armies had invaded German-held Europe from all sides. Nazi forces engaged in numerous violent acts during the war, including the systematic murder of as many as 17 million civilians, an estimated six million of whom were Jews targeted in the Holocaust and between 500,000 and 1,500,000 were Romanis. Others targeted included ethnic Poles, Soviet civilians, Soviet prisoners of war, people with disabilities, homosexuals, Jehovah's Witnesses, and other political and religious opponents. In the final days of the war, during the Battle of Berlin in 1945, Hitler married his long-time mistress Eva Braun and, to avoid capture by Soviet forces less than two days later, the two committed suicide on 30 April 1945.

Hitler's father, Alois Hitler, was an illegitimate child of Maria Anna Schicklgruber so his paternity was not listed on his birth certificate and he bore his mother's surname. In 1842, Johann Georg Hiedler married Maria and in 1876 Alois testified before a notary and three witnesses that Johann was his father. At age 39, Alois took the surname Hitler. This surname was variously spelled Hiedler, Hüttler, Huettler and Hitler, and was probably regularized to Hitler by a clerk. The origin of the name is either "one who lives in a hut" (Standard German Hütte), "shepherd" (Standard German hüten "to guard", English heed), or is from the Slavic word Hidlar and Hidlarcek. (Regarding the first two theories: some German dialects make little or no distinction between the ü-sound and the i-sound.)

Despite this testimony, Alois' paternity has been the subject of controversy. After receiving a "blackmail letter" from Hitler's nephew William Patrick Hitler threatening to reveal embarrassing information about Hitler's family tree, Nazi Party lawyer Hans Frank investigated, and, in his memoirs, claimed to have uncovered letters revealing that Alois' mother, Maria Schicklgruber, was employed as a housekeeper for a Jewish family in Graz and that the family's 19-year-old son, Leopold Frankenberger, fathered Alois. No evidence has ever been produced to support Frank's claim, and Frank himself said Hitler's full Aryan blood was obvious. Frank's claims were widely believed in the 1950s, but by the 1990s, were generally doubted by historians. Ian Kershaw dismisses the Frankenberger story as a "smear" by Hitler's enemies, noting that all Jews had been expelled from Graz in the 15th century and were not allowed to return until well after Alois was born.

Adolf Hitler was born on 20 April 1889 at half-past six in the evening at the Gasthof zum Pommer, an inn in Braunau am Inn, Austria–Hungary, the fourth of Alois and Klara Hitler's six children. At the age of three, his family moved to Kapuzinerstrasse 5 in Passau, Germany, where the young Hitler would acquire Lower Bavarian rather than Austrian as his lifelong native dialect. In 1894, the family moved to Leonding near Linz, then in June 1895, Alois retired to a small landholding at Hafeld near Lambach, where he tried his hand at farming and beekeeping. During this time, the young Hitler attended school in nearby Fischlham. As a child, he tirelessly played "Cowboys and Indians" and, by his own account, became fixated on war after finding a picture book about the Franco-Prussian War in his father's things. He wrote in Mein Kampf: "It was not long before the great historic struggle had become my greatest spiritual experience. From then on, I became more and more enthusiastic about everything that was in any way connected with war or, for that matter, with soldiering." His father's efforts at Hafeld ended in failure and the family moved to Lambach in 1897. There, Hitler attended a Catholic school located in an 11th-century Benedictine cloister whose walls were engraved in a number of places with crests containing the symbol of the swastika. It was in Lambach that the eight year-old Hitler sang in the church choir, took singing lessons, and even entertained the fantasy of one day becoming a priest. In 1898, the family returned permanently to Leonding.

His younger brother Edmund died of measles on 2 February 1900, causing permanent changes in Hitler. He went from a confident, outgoing boy who found school easy, to a morose, detached, sullen boy who constantly battled his father and his teachers. Hitler was close to his mother, but had a troubled relationship with his authoritarian father, who frequently beat him, especially in the years after Alois' retirement and disappointing farming efforts. Alois wanted his son to follow in his footsteps as an Austrian customs official, and this became a huge source of conflict between them. Despite his son's pleas to go to classical high school and become an artist, his father sent him to the Realschule in Linz, a technical high school of about 300 students, in September 1900. Hitler rebelled, and in Mein Kampf confessed to failing his first year in hopes that once his father saw "what little progress I was making at the technical school he would let me devote myself to the happiness I dreamed of." But Alois never relented and Hitler became even more bitter and rebellious.

For young Hitler, German Nationalism quickly became an obsession, and a way to rebel against his father, who proudly served the Austrian government. Most people who lived along the German-Austrian border considered themselves German-Austrians, but Hitler expressed loyalty only to Germany. In defiance of the Austrian monarchy, and his father who continually expressed loyalty to it, Hitler and his young friends liked to use the German greeting "Heil", and sing the German anthem "Deutschland Über Alles" instead of the Austrian Imperial anthem.

After Alois' sudden death on 3 January 1903, Hitler's behaviour at the technical school became even more disruptive, and he was asked to leave. He enrolled at the Realschule in Steyr in 1904, but upon completing his second year, he and his friends went out for a night of celebration and drinking, and an intoxicated Hitler tore his school certificate into four pieces and used it as toilet paper. When someone turned the stained certificate in to the school's director, he "... gave him such a dressing-down that the boy was reduced to shivering jelly. It was probably the most painful and humiliating experience of his life." Hitler was expelled, never to return to school again.

At age 15, Hitler took part in his First Holy Communion on Whitsunday, 22 May 1904, at the Linz Cathedral. His sponsor was Emanuel Lugert, a friend of his late father.

From 1905 on, Hitler lived a bohemian life in Vienna on an orphan's pension and support from his mother. He was rejected twice by the Academy of Fine Arts Vienna (1907 – 1908), citing "unfitness for painting", and was told his abilities lay instead in the field of architecture. His memoirs reflect a fascination with the subject:

The purpose of my trip was to study the picture gallery in the Court Museum, but I had eyes for scarcely anything but the Museum itself. From morning until late at night, I ran from one object of interest to another, but it was always the buildings which held my primary interest.

Following the school rector's recommendation, he too became convinced this was his path to pursue, yet he lacked the proper academic preparation for architecture school:

In a few days I myself knew that I should some day become an architect. To be sure, it was an incredibly hard road; for the studies I had neglected out of spite at the Realschule were sorely needed. One could not attend the Academy's architectural school without having attended the building school at the Technic, and the latter required a high-school degree. I had none of all this. The fulfilment of my artistic dream seemed physically impossible.

On 21 December 1907, Hitler's mother died of breast cancer at age 47. Ordered by a court in Linz, Hitler gave his share of the orphans' benefits to his sister Paula. When he was 21, he inherited money from an aunt. He struggled as a painter in Vienna, copying scenes from postcards and selling his paintings to merchants and tourists. After being rejected a second time by the Academy of Arts, Hitler ran out of money. In 1909, he lived in a shelter for the homeless. By 1910, he had settled into a house for poor working men on Meldemannstraße. Another resident of the house, Reinhold Hanisch, sold Hitler's paintings until the two men had a bitter falling-out.

Hitler said he first became an anti-Semite in Vienna, which had a large Jewish community, including Orthodox Jews who had fled the pogroms in Russia. According to childhood friend August Kubizek, however, Hitler was a "confirmed anti-Semite" before he left Linz. Vienna at that time was a hotbed of traditional religious prejudice and 19th century racism. Hitler may have been influenced by the writings of the ideologist and anti-Semite Lanz von Liebenfels and polemics from politicians such as Karl Lueger, founder of the Christian Social Party and Mayor of Vienna, the composer Richard Wagner, and Georg Ritter von Schönerer, leader of the pan-Germanic Away from Rome! movement. Hitler claims in Mein Kampf that his transition from opposing antisemitism on religious grounds to supporting it on racial grounds came from having seen an Orthodox Jew.

There were very few Jews in Linz. In the course of centuries the Jews who lived there had become Europeanised in external appearance and were so much like other human beings that I even looked upon them as Germans. The reason why I did not then perceive the absurdity of such an illusion was that the only external mark which I recognized as distinguishing them from us was the practice of their strange religion. As I thought that they were persecuted on account of their faith my aversion to hearing remarks against them grew almost into a feeling of abhorrence. I did not in the least suspect that there could be such a thing as a systematic antisemitism. Once, when passing through the inner City, I suddenly encountered a phenomenon in a long caftan and wearing black side-locks. My first thought was: Is this a Jew? They certainly did not have this appearance in Linz. I carefully watched the man stealthily and cautiously but the longer I gazed at the strange countenance and examined it feature by feature, the more the question shaped itself in my brain: Is this a German?

If this account is true, Hitler apparently did not act on his new belief. He often was a guest for dinner in a noble Jewish house, and he interacted well with Jewish merchants who tried to sell his paintings. Hitler may also have been influenced by Martin Luther's On the Jews and their Lies. In Mein Kampf, Hitler refers to Martin Luther as a great warrior, a true statesman, and a great reformer, alongside Richard Wagner and Frederick the Great. Wilhelm Röpke, writing after the Holocaust, concluded that "without any question, Lutheranism influenced the political, spiritual and social history of Germany in a way that, after careful consideration of everything, can be described only as fateful."

Hitler claimed that Jews were enemies of the Aryan race. He held them responsible for Austria's crisis. He also identified certain forms of socialism and Bolshevism, which had many Jewish leaders, as Jewish movements, merging his antisemitism with anti-Marxism. Later, blaming Germany's military defeat in World War I on the 1918 revolutions, he considered Jews the culprits of Imperial Germany's downfall and subsequent economic problems as well.

Generalising from tumultuous scenes in the parliament of the multi-national Austrian monarchy, he decided that the democratic parliamentary system was unworkable. However, according to August Kubizek, his one-time roommate, he was more interested in Wagner's operas than in his politics.

Hitler received the final part of his father's estate in May 1913 and moved to Munich. He wrote in Mein Kampf that he had always longed to live in a "real" German city. In Munich, he became more interested in architecture and, he says, the writings of Houston Stewart Chamberlain. Moving to Munich also helped him escape military service in Austria for a time, but the Munich police (acting in cooperation with the Austrian authorities) eventually arrested him. After a physical exam and a contrite plea, he was deemed unfit for service and allowed to return to Munich. However, when Germany entered World War I in August 1914, he petitioned King Ludwig III of Bavaria for permission to serve in a Bavarian regiment. This request was granted, and Adolf Hitler enlisted in the Bavarian army.

Hitler served in France and Belgium in the 16th Bavarian Reserve Regiment (called Regiment List after its first commander), ending the war as a Gefreiter (equivalent at the time to a lance corporal in the British and private first class in the American armies). He was a runner, "a dangerous enough job" on the Western Front, and was often exposed to enemy fire. He participated in a number of major battles on the Western Front, including the First Battle of Ypres, the Battle of the Somme, the Battle of Arras and the Battle of Passchendaele. The Battle of Ypres (October 1914), which became known in Germany as the Kindermord bei Ypern (Massacre of the Innocents) saw approximately 40,000 men (between a third and a half) of the nine infantry divisions present killed in 20 days, and Hitler's own company of 250 reduced to 42 by December. Biographer John Keegan has said that this experience drove Hitler to become aloof and withdrawn for the remaining years of war.

Hitler was twice decorated for bravery. He received the Iron Cross, Second Class, in 1914 and Iron Cross, First Class, in 1918, an honour rarely given to a Gefreiter. However, because the regimental staff thought Hitler lacked leadership skills, he was never promoted to Unteroffizier (equivalent to a British corporal). Other historians say that the reason he was not promoted is that he was not a German citizen. His duties at regimental headquarters, while often dangerous, gave Hitler time to pursue his artwork. He drew cartoons and instructional drawings for an army newspaper. In 1916, he was wounded in either the groin area or the left thigh during the Battle of the Somme, but returned to the front in March 1917. He received the Wound Badge later that year. A noted German historian and author, Sebastian Haffner, referring to Hitler's experience at the front, suggests he did have at least some understanding of the military.

On 15 October 1918, Hitler was admitted to a field hospital, temporarily blinded by a mustard gas attack. The English psychologist David Lewis and Bernhard Horstmann suggest the blindness may have been the result of a conversion disorder (then known as "hysteria"). Citing contemporary witnesses, Claus Hant concludes that the psychotic episode led Hitler to believe that he had received a divine mission. In fact, Hitler said it was during this experience that he became convinced the purpose of his life was to "save Germany." Some scholars, notably Lucy Dawidowicz, argue that an intention to exterminate Europe's Jews was fully formed in Hitler's mind at this time, though he probably had not thought through how it could be done. Most historians think the decision was made in 1941, and some think it came as late as 1942. Two passages in Mein Kampf mention the use of poison gas:

At the beginning of the Great War, or even during the War, if twelve or fifteen thousand of these Jews who were corrupting the nation had been forced to submit to poison-gas . . . then the millions of sacrifices made at the front would not have been in vain.

These tactics are based on an accurate estimation of human weakness and must lead to success, with almost mathematical certainty, unless the other side also learns how to fight poison gas with poison gas. The weaker natures must be told that here it is a case of to be or not to be.

Hitler had long admired Germany, and during the war he had become a passionate German patriot, although he did not become a German citizen until 1932. Hitler found the war to be 'the greatest of all experiences' and afterwards he was praised by a number of his commanding officers for his bravery. He was shocked by Germany's capitulation in November 1918 even while the German army still held enemy territory. Like many other German nationalists, Hitler believed in the Dolchstoßlegende ("dagger-stab legend") which claimed that the army, "undefeated in the field," had been "stabbed in the back" by civilian leaders and Marxists back on the home front. These politicians were later dubbed the November Criminals.

The Treaty of Versailles deprived Germany of various territories, demilitarised the Rhineland and imposed other economically damaging sanctions. The treaty re-created Poland, which even moderate Germans regarded as an outrage. The treaty also blamed Germany for all the horrors of the war, something which major historians such as John Keegan now consider at least in part to be victor's justice: most European nations in the run-up to World War I had become increasingly militarised and were eager to fight. The culpability of Germany was used as a basis to impose reparations on Germany (the amount was repeatedly revised under the Dawes Plan, the Young Plan, and the Hoover Moratorium). Germany in turn perceived the treaty and especially, Article 231 the paragraph on the German responsibility for the war, as a humiliation. For example, there was a nearly total demilitarisation of the armed forces, allowing Germany only six battleships, no submarines, no air force, an army of 100,000 without conscription and no armoured vehicles. The treaty was an important factor in both the social and political conditions encountered by Hitler and his Nazis as they sought power. Hitler and his party used the signing of the treaty by the "November Criminals" as a reason to build up Germany so that it could never happen again. He also used the "November Criminals" as scapegoats, although at the Paris peace conference, these politicians had had very little choice in the matter.

After World War I, Hitler remained in the army and returned to Munich, where he – in contrast to his later declarations – attended the funeral march for the murdered Bavarian prime minister Kurt Eisner. After the suppression of the Bavarian Soviet Republic, he took part in "national thinking" courses organized by the Education and Propaganda Department (Dept Ib/P) of the Bavarian Reichswehr Group, Headquarters 4 under Captain Karl Mayr. Scapegoats were found in "international Jewry", communists, and politicians across the party spectrum, especially the parties of the Weimar Coalition.

In July 1919, Hitler was appointed a Verbindungsmann (police spy) of an Aufklärungskommando (Intelligence Commando) of the Reichswehr, both to influence other soldiers and to infiltrate a small party, the German Workers' Party (DAP). During his inspection of the party, Hitler was impressed with founder Anton Drexler's anti-semitic, nationalist, anti-capitalist and anti-Marxist ideas, which favoured a strong active government, a "non-Jewish" version of socialism and mutual solidarity of all members of society. Drexler was impressed with Hitler's oratory skills and invited him to join the party. Hitler joined DAP on 12 September 1919 and became the party's 55th member. He was also made the seventh member of the executive committee. Years later, he claimed to be the party's seventh overall member, but it has been established that this claim is false.

Here Hitler met Dietrich Eckart, one of the early founders of the party and member of the occult Thule Society. The Thule members believed in the coming of a “German Messiah” who would redeem Germany after its defeat in World War I. Dietrich Eckart expressed his anticipation in a poem he published months before he met Hitler for the first time. In the poem, Eckart refers to ‘the Great One’, ‘the Nameless One’, ‘Whom all can sense but no one saw’. When Eckart met Hitler in 1919 he believed to have found the prophesied redeemer. Eckart became Hitler's mentor, exchanging ideas with him, teaching him how to dress and speak, and introducing him to a wide range of people. Hitler thanked Eckart by paying tribute to him in the second volume of Mein Kampf. To increase the party's appeal, the party changed its name to the Nationalsozialistische Deutsche Arbeiterpartei or National Socialist German Workers Party (abbreviated NSDAP).

Hitler was discharged from the army in March 1920 and with his former superiors' continued encouragement began participating full time in the party's activities. By early 1921, Hitler was becoming highly effective at speaking in front of large crowds. In February, Hitler spoke before a crowd of nearly six thousand in Munich. To publicize the meeting, he sent out two truckloads of party supporters to drive around with swastikas, cause a commotion and throw out leaflets, their first use of this tactic. Hitler gained notoriety outside of the party for his rowdy, polemic speeches against the Treaty of Versailles, rival politicians (including monarchists, nationalists and other non-internationalist socialists) and especially against Marxists and Jews.

The NSDAP was centred in Munich, a hotbed of German nationalists who included Army officers determined to crush Marxism and undermine the Weimar republic. Gradually they noticed Hitler and his growing movement as a suitable vehicle for their goals. Hitler traveled to Berlin to visit nationalist groups during the summer of 1921, and in his absence there was a revolt among the DAP leadership in Munich. The party was run by an executive committee whose original members considered Hitler to be overbearing. They formed an alliance with a group of socialists from Augsburg. Hitler rushed back to Munich and countered them by tendering his resignation from the party on 11 July 1921. When they realized the loss of Hitler would effectively mean the end of the party, he seized the moment and announced he would return on the condition that he replace Drexler as party chairman, with unlimited powers. Infuriated committee members (including Drexler) held out at first. Meanwhile an anonymous pamphlet appeared entitled Adolf Hitler: Is he a traitor?, attacking Hitler's lust for power and criticizing the violent men around him. Hitler responded to its publication in a Munich newspaper by suing for libel and later won a small settlement. The executive committee of the NSDAP eventually backed down and Hitler's demands were put to a vote of party members. Hitler received 543 votes for and only one against. At the next gathering on 29 July 1921, Adolf Hitler was introduced as Führer of the National Socialist German Workers' Party, marking the first time this title was publicly used.

Hitler's beer hall oratory, attacking Jews, social democrats, liberals, reactionary monarchists, capitalists and communists, began attracting adherents. Early followers included Rudolf Hess, the former air force pilot Hermann Göring, and the army captain Ernst Röhm, who eventually became head of the Nazis' paramilitary organization, the SA (Sturmabteilung, or "Storm Division"), which protected meetings and attacked political opponents. As well, Hitler assimilated independent groups, such as the Nuremberg-based Deutsche Werkgemeinschaft, led by Julius Streicher, who became Gauleiter of Franconia. Hitler attracted the attention of local business interests, was accepted into influential circles of Munich society, and became associated with wartime General Erich Ludendorff during this time.

Encouraged by this early support, Hitler decided to use Ludendorff as a front in an attempted coup, later known as the "Beer Hall Putsch" (sometimes as the "Hitler Putsch" or "Munich Putsch"). The Nazi Party had copied Italy's fascists in appearance and had adopted some of their policies, and in 1923, Hitler wanted to emulate Benito Mussolini's "March on Rome" by staging his own "Campaign in Berlin". Hitler and Ludendorff obtained the clandestine support of Gustav von Kahr, Bavaria's de facto ruler, along with leading figures in the Reichswehr and the police. As political posters show, Ludendorff, Hitler and the heads of the Bavarian police and military planned on forming a new government. On 8 November 1923, Hitler and the SA stormed a public meeting headed by Kahr in the Bürgerbräukeller, a large beer hall in Munich. He declared that he had set up a new government with Ludendorff and demanded, at gunpoint, the support of Kahr and the local military establishment for the destruction of the Berlin government. Kahr withdrew his support and fled to join the opposition to Hitler at the first opportunity. The next day, when Hitler and his followers marched from the beer hall to the Bavarian War Ministry to overthrow the Bavarian government as a start to their "March on Berlin", the police dispersed them. Sixteen NSDAP members were killed.

Hitler fled to the home of Ernst Hanfstaengl and contemplated suicide. He was soon arrested for high treason. Alfred Rosenberg became temporary leader of the party. During Hitler's trial, he was given almost unlimited time to speak, and his popularity soared as he voiced nationalistic sentiments in his defence speech. A Munich personality became a nationally known figure. On 1 April 1924, Hitler was sentenced to five years' imprisonment at Landsberg Prison. Hitler received favoured treatment from the guards and had much fan mail from admirers. He was pardoned and released from jail on 20 December 1924, by order of the Bavarian Supreme Court on 19 December, which issued its final rejection of the state prosecutor's objections to Hitler's early release. Including time on remand, he had served little more than one year of his sentence. On 28 June 1925, Hitler wrote a letter from Uffing to the editor of The Nation in New York City stating how long he had been in prison at "Sandberg a. S." [sic] and how much his privileges had been revoked.

While at Landsberg he dictated most of the first volume of Mein Kampf (My Struggle, originally entitled Four and a Half Years of Struggle against Lies, Stupidity, and Cowardice) to his deputy Rudolf Hess. The book, dedicated to Thule Society member Dietrich Eckart, was an autobiography and an exposition of his ideology. Mein Kampf was influenced by The Passing of the Great Race by Madison Grant which Hitler called "my Bible." It was published in two volumes in 1925 and 1926, selling about 240,000 copies between 1925 and 1934. By the end of the war, about 10 million copies had been sold or distributed (newlyweds and soldiers received free copies). Hitler spent years dodging taxes on the royalties of his book and had accumulated a tax debt of about 405,500 Reichsmarks (€6 million in today's money) by the time he became chancellor (at which time his debt was waived). The copyright of Mein Kampf in Europe is claimed by the Free State of Bavaria and scheduled to end on 31 December 2015. Reproductions in Germany are authorized only for scholarly purposes and in heavily commented form. The situation is, however, unclear. Historian Werner Maser, in an interview with Bild am Sonntag has stated that Peter Raubal, son of Hitler's nephew, Leo Raubal, would have a strong legal case for winning the copyright from Bavaria if he pursued it. Raubal has stated he wants no part of the rights to the book, which could be worth millions of euros. The uncertain status has led to contested trials in Poland and Sweden. Mein Kampf, however, is published in the U.S., as well as in other countries such as Turkey and Israel, by publishers with various political positions.

At the time of Hitler's release, the political situation in Germany had calmed and the economy had improved, which hampered Hitler's opportunities for agitation. Though the "Hitler Putsch" had given Hitler some national prominence, his party's mainstay was still Munich. The NSDAP and its organs were banned in Bavaria after the collapse of the putsch. Hitler convinced Heinrich Held, Prime Minister of Bavaria, to lift the ban, based on representations that the party would now only seek political power through legal means. Even though the ban on the NSDAP was removed effective 16 February 1925, Hitler incurred a new ban on public speaking as a result of an inflammatory speech. Since Hitler was banned from public speeches, he appointed Gregor Strasser, who in 1924 had been elected to the Reichstag, as Reichsorganisationsleiter, authorizing him to organize the party in northern Germany. Strasser, joined by his younger brother Otto and Joseph Goebbels, steered an increasingly independent course, emphasizing the socialist element in the party's programme. The Arbeitsgemeinschaft der Gauleiter Nord-West became an internal opposition, threatening Hitler's authority, but this faction was defeated at the Bamberg Conference in 1926, during which Goebbels joined Hitler. After this encounter, Hitler centralized the party even more and asserted the Führerprinzip ("Leader principle") as the basic principle of party organization. Leaders were not elected by their group but were rather appointed by their superior and were answerable to them while demanding unquestioning obedience from their inferiors. Consistent with Hitler's disdain for democracy, all power and authority devolved from the top down.

A key element of Hitler's appeal was his ability to evoke a sense of offended national pride caused by the Treaty of Versailles imposed on the defeated German Empire by the Western Allies. Germany had lost economically important territory in Europe along with its colonies and in admitting to sole responsibility for the war had agreed to pay a huge reparations bill totaling 132 billion marks. Most Germans bitterly resented these terms, but early Nazi attempts to gain support by blaming these humiliations on "international Jewry" were not particularly successful with the electorate. The party learned quickly, and soon a more subtle propaganda emerged, combining antisemitism with an attack on the failures of the "Weimar system" and the parties supporting it. Having failed in overthrowing the Republic by a coup, Hitler pursued a "strategy of legality": this meant formally adhering to the rules of the Weimar Republic until he had legally gained power. He would then use the institutions of the Weimar Republic to destroy it and establish himself as dictator. Some party members, especially in the paramilitary SA, opposed this strategy; Röhm and others ridiculed Hitler as "Adolphe Legalité".

The political turning point for Hitler came when the Great Depression hit Germany in 1930. The Weimar Republic had never been firmly rooted and was openly opposed by right-wing conservatives (including monarchists), communists and the Nazis. As the parties loyal to the democratic, parliamentary republic found themselves unable to agree on counter-measures, their grand coalition broke up and was replaced by a minority cabinet. The new Chancellor, Heinrich Brüning of the Roman Catholic Centre Party, lacking a majority in parliament, had to implement his measures through the president's emergency decrees. Tolerated by the majority of parties, this rule by decree would become the norm over a series of unworkable parliaments and paved the way for authoritarian forms of government. The Reichstag's initial opposition to Brüning's measures led to premature elections in September 1930. The republican parties lost their majority and their ability to resume the grand coalition, while the Nazis suddenly rose from relative obscurity to win 18.3% of the vote along with 107 seats. In the process, they jumped from the ninth-smallest party in the chamber to the second largest.

In September–October 1930, Hitler appeared as a major defence witness at the trial in Leipzig of two junior Reichswehr officers charged with membership of the Nazi Party, which at that time was forbidden to Reichswehr personnel. The two officers, Leutnants Richard Scheringer and Hans Ludin, admitted quite openly to Nazi Party membership, and used as their defence that the Nazi Party membership should not be forbidden to those serving in the Reichswehr. When the Prosecution argued that the Nazi Party was a dangerous revolutionary force, one of the defence lawyers, Hans Frank, had Hitler brought to the stand to prove that the Nazi Party was a law-abiding party. During his testimony, Hitler insisted that his party was determined to come to power legally, that the phrase "National Revolution" was only to be interpreted "politically", and that his Party was a friend, not an enemy of the Reichswehr. Hitler's testimony of 25 September 1930 won him many admirers within the ranks of the officer corps.

Brüning's measures of budget consolidation and financial austerity brought little economic improvement and were extremely unpopular. Under these circumstances, Hitler appealed to the bulk of German farmers, war veterans and the middle class, who had been hard-hit by both the inflation of the 1920s and the unemployment of the Depression. In September 1931, Hitler's niece Geli Raubal was found dead in her bedroom in his Munich apartment (his half-sister Angela and her daughter Geli had been with him in Munich since 1929), an apparent suicide. Geli, who was believed to be in some sort of romantic relationship with Hitler, was 19 years younger than he was and had used his gun. His niece's death is viewed as a source of deep, lasting pain for him.

In 1932, Hitler intended to run against the aging President Paul von Hindenburg in the scheduled presidential elections. His 27 January 1932 speech to the Industry Club in Düsseldorf won him, for the first time, support from a broad swath of Germany's most powerful industrialists. Though Hitler had left Austria in 1913 and had renounced his Austrian citizenship in 1925, he still had not acquired German citizenship and hence could not run for public office. On 25 February, however, the interior minister of the Brunswick, a Nazi (the Nazis were part of a right-wing coalition governing the state) appointed Hitler as administrator for the state's delegation to the Reichsrat in Berlin. This appointment made Hitler a citizen of Brunswick. In those days, the states conferred citizenship, so this automatically made Hitler a citizen of Germany as well and thus eligible to run for president. The new German citizen ran against Hindenburg, who was supported by a broad range of nationalist, monarchist, Catholic, republican and even social democratic parties. Another candidate was a Communist and member of a fringe right-wing party. Hitler's campaign was called "Hitler über Deutschland" (Hitler over Germany). The name had a double meaning; besides a reference to his dictatorial ambitions, it referred to the fact that he campaigned by aircraft. Hitler came in second on both rounds, attaining more than 35% of the vote during the second one in April. Although he lost to Hindenburg, the election established Hitler as a realistic alternative in German politics.

Meanwhile, Papen tried to get his revenge on Schleicher by working toward the General's downfall, through forming an intrigue with the camarilla and Alfred Hugenberg, media mogul and chairman of the DNVP. Also involved were Hjalmar Schacht, Fritz Thyssen and other leading German businessmen and international bankers. They financially supported the Nazi Party, which had been brought to the brink of bankruptcy by the cost of heavy campaigning. The businessmen wrote letters to Hindenburg, urging him to appoint Hitler as leader of a government "independent from parliamentary parties" which could turn into a movement that would "enrapture millions of people."

Finally, the president reluctantly agreed to appoint Hitler Chancellor of a coalition government formed by the NSDAP and DNVP. However, the Nazis were to be contained by a framework of conservative cabinet ministers, most notably by Papen as Vice-Chancellor and by Hugenberg as Minister of the Economy. The only other Nazi besides Hitler to get a portfolio was Wilhelm Frick, who was given the relatively powerless interior ministry (in Germany at the time, most powers wielded by the interior minister in other countries were held by the interior ministers of the states). As a concession to the Nazis, Göring was named minister without portfolio. While Papen intended to use Hitler as a figurehead, the Nazis gained key positions.

On the morning of 30 January 1933, in Hindenburg's office, Adolf Hitler was sworn in as Chancellor during what some observers later described as a brief and simple ceremony. His first speech as Chancellor took place on 10 February. The Nazis' seizure of power subsequently became known as the Machtergreifung or Machtübernahme.

Having become Chancellor, Hitler foiled all attempts by his opponents to gain a majority in parliament. Because no single party could gain a majority, Hitler persuaded President Hindenburg to dissolve the Reichstag again. Elections were scheduled for early March, but on 27 February 1933, the Reichstag building was set on fire. Since a Dutch independent communist was found in the building, the fire was blamed on a communist plot. The government reacted with the Reichstag Fire Decree of 28 February which suspended basic rights, including habeas corpus. Under the provisions of this decree, the German Communist Party (KPD) and other groups were suppressed, and Communist functionaries and deputies were arrested, forced to flee, or murdered. Campaigning continued, with the Nazis making use of paramilitary violence, anti-communist hysteria, and the government's resources for propaganda. On election day, 6 March, the NSDAP increased its result to 43.9% of the vote, remaining the largest party, but its victory was marred by its failure to secure an absolute majority, necessitating maintaining a coalition with the DNVP.

On 21 March, the new Reichstag was constituted with an opening ceremony held at Potsdam's garrison church. This "Day of Potsdam" was staged to demonstrate reconciliation and unity between the revolutionary Nazi movement and "Old Prussia" with its elites and virtues. Hitler appeared in a tail coat and humbly greeted the aged President Hindenburg. Because of the Nazis' failure to obtain a majority on their own, Hitler's government confronted the newly elected Reichstag with the Enabling Act that would have vested the cabinet with legislative powers for a period of four years. Though such a bill was not unprecedented, this act was different since it allowed for deviations from the constitution. Since the bill required a ⅔ majority in order to pass, the government needed the support of other parties. The position of the Centre Party, the third largest party in the Reichstag, turned out to be decisive: under the leadership of Ludwig Kaas, the party decided to vote for the Enabling Act. It did so in return for the government's oral guarantees regarding the Church's liberty, the concordats signed by German states and the continued existence of the Centre Party.

On 23 March, the Reichstag assembled in a replacement building under extremely turbulent circumstances. Some SA men served as guards within while large groups outside the building shouted slogans and threats toward the arriving deputies. Kaas announced that the Centre Party would support the bill with "concerns put aside," while Social Democrat Otto Wels denounced the act in his speech. At the end of the day, all parties except the Social Democrats voted in favour of the bill. The Communists, as well as some Social Democrats, were barred from attending. The Enabling Act, combined with the Reichstag Fire Decree, transformed Hitler's government into a legal dictatorship.

“	At the risk of appearing to talk nonsense I tell you that the Nazi movement will go on for 1,000 years! ... Don't forget how people laughed at me 15 years ago when I declared that one day I would govern Germany. They laugh now, just as foolishly, when I declare that I shall remain in power!	”
—Adolf Hitler to a British correspondent in Berlin, June 1934

With this combination of legislative and executive power, Hitler's government further suppressed the remaining political opposition. The Communist Party of Germany and the Social Democratic Party (SPD) were banned, while all other political parties were forced to dissolve themselves. Finally, on 14 July, the Nazi Party was declared the only legal party in Germany.

Hitler used the SA paramilitary to push Hugenberg into resigning, and proceeded to politically isolate Vice-Chancellor Papen. Because the SA's demands for political and military power caused much anxiety among military and political leaders, Hitler used allegations of a plot by the SA leader Ernst Röhm to purge the SA's leadership during the Night of the Long Knives. As well, opponents unconnected with the SA were murdered, notably Gregor Strasser and former Chancellor Kurt von Schleicher.

President Paul von Hindenburg died on 2 August 1934. Rather than call new elections as required by the constitution, Hitler's cabinet passed a law proclaiming the presidency vacant and transferred the role and powers of the head of state to Hitler as Führer und Reichskanzler (leader and chancellor). This action effectively removed the last legal remedy by which Hitler could be dismissed – and with it, nearly all institutional checks and balances on his power. On 19 August a plebiscite approved the merger of the presidency with the chancellorship winning 84.6% of the electorate. This action technically violated both the constitution and the Enabling Act. The constitution had been amended in 1932 to make the president of the High Court of Justice, not the chancellor, acting president until new elections could be held. The Enabling Act specifically barred Hitler from taking any action that tampered with the presidency. However, no one dared object. As head of state, Hitler now became Supreme Commander of the armed forces. When it came time for the soldiers and sailors to swear the traditional loyalty oath, it had been altered into an oath of personal loyalty to Hitler. Normally, soldiers and sailors swear loyalty to the holder of the office of supreme commander/commander-in-chief, not a specific person.

In 1938, Hitler forced the resignation of his War Minister (formerly Defense Minister), Werner von Blomberg, after evidence surfaced that Blomberg's new wife had a criminal past. Prior to removing Blomberg, Hitler and his clique removed army commander Werner von Fritsch on suspicion of homosexuality. Hitler replaced the Ministry of War with the Oberkommando der Wehrmacht (High Command of the Armed Forces, or OKW), headed by the pliant General Wilhelm Keitel. More importantly, Hitler announced he was assuming personal command of the armed forces. He took over Blomberg's other old post, that of Commander-in-Chief of the Armed Forces, for himself. He was already Supreme Commander by virtue of holding the powers of the president. The next day, the newspapers announced, "Strongest concentration of powers in Führer's hands!"

Having secured supreme political power, Hitler went on to gain public support by convincing most Germans he was their saviour from the economic Depression, the Versailles treaty, communism, the "Judeo-Bolsheviks", and other "undesirable" minorities. The Nazis eliminated opposition through a process known as Gleichschaltung ("bringing into line").

Hitler oversaw one of the greatest expansions of industrial production and civil improvement Germany had ever seen, mostly based on debt flotation and expansion of the military. Nazi policies toward women strongly encouraged them to stay at home to bear children and keep house. In a September 1934 speech to the National Socialist Women's Organization, Adolf Hitler argued that for the German woman her "world is her husband, her family, her children, and her home." This policy was reinforced by bestowing the Cross of Honor of the German Mother on women bearing four or more babies. The unemployment rate was cut substantially, mostly through arms production and sending women home so that men could take their jobs. Given this, claims that the German economy achieved near full employment are at least partly artefacts of propaganda from the era. Much of the financing for Hitler's reconstruction and rearmament came from currency manipulation by Hjalmar Schacht, including the clouded credits through the Mefo bills.

Hitler oversaw one of the largest infrastructure-improvement campaigns in German history, with the construction of dozens of dams, autobahns, railroads, and other civil works. Hitler's policies emphasised the importance of family life: men were the "breadwinners", while women's priorities were to lie in bringing up children and in household work. This revitalising of industry and infrastructure came at the expense of the overall standard of living, at least for those not affected by the chronic unemployment of the later Weimar Republic, since wages were slightly reduced in pre-World War II years, despite a 25% increase in the cost of living. Laborers and farmers, the traditional voters of the NSDAP, however, saw an increase in their standard of living.

Hitler's government sponsored architecture on an immense scale, with Albert Speer becoming famous as the first architect of the Reich. While important as an architect in implementing Hitler's classicist reinterpretation of German culture, Speer proved much more effective as armaments minister during the last years of World War II. In 1936, Berlin hosted the summer Olympic games, which were opened by Hitler and choreographed to demonstrate Aryan superiority over all other races, achieving mixed results.

Although Hitler made plans for a Breitspurbahn ("broad gauge railroad network"), they were preempted by World War II. Had the railroad been built, its gauge would have been three metres, even wider than the old Great Western Railway of Britain.

Hitler contributed slightly to the design of the car that later became the Volkswagen Beetle and charged Ferdinand Porsche with its design and construction. Production was deferred because of the war.

Hitler considered Sparta to be the first National Socialist state, and praised its early eugenics treatment of deformed children.

On 20 April 1939, a lavish celebration was held in honour of Hitler's 50th birthday, featuring military parades, visits from foreign dignitaries, thousands of flaming torches and Nazi banners.

An important historical debate about Hitler's economic policies concerns the "modernization" debate. Historians such as David Schoenbaum and Henry Ashby Turner have argued that social and economic polices under Hitler were modernization carried out in pursuit of anti-modern goals. Other groups of historians centred around Rainer Zitelmann have contended that Hitler had a deliberate strategy of pursuing a revolutionary modernization of German society.

In a meeting with his leading generals and admirals on 3 February 1933, Hitler spoke of "conquest of Lebensraum in the East and its ruthless Germanisation" as his ultimate foreign policy objectives. In March 1933, the first major statement of German foreign policy aims appeared with the memo submitted to the German Cabinet by the State Secretary at the Auswärtiges Amt (Foreign Office), Prince Bernhard Wilhelm von Bülow (not to be confused with his more famous uncle, the former Chancellor Bernhard von Bülow), which advocated Anschluss with Austria, the restoration of the frontiers of 1914, the rejection of the Part V of Versailles, the return of the former German colonies in Africa, and a German zone of influence in Eastern Europe as goals for the future. Hitler found the goals in Bülow's memo to be too modest. In March 1933, to resolve the deadlock between the French demand for sécurité ("security") and the German demand for gleichberechtigung ("equality of armaments") at the World Disarmament Conference in Geneva, Switzerland, the British Prime Minister Ramsay MacDonald presented the compromise "MacDonald Plan". Hitler endorsed the "MacDonald Plan", correctly guessing that nothing would come of it, and that in the interval he could win some goodwill in London by making his government appear moderate, and the French obstinate.

In May 1933, Hitler met with Herbert von Dirksen, the German Ambassador in Moscow. Dirksen advised the Führer that he was allowing relations with the Soviet Union to deteriorate to a unacceptable extent, and advised to take immediate steps to repair relations with the Soviets. Much to Dirksen's intense disappointment, Hitler informed that he wished for an anti-Soviet understanding with Poland, which Dirksen protested implied recognition of the German-Polish border, leading Hitler to state he was after much greater things than merely overturning the Treaty of Versailles.

In June 1933, Hitler was forced to disavow Alfred Hugenberg of the German National People's Party, who while attending the London World Economic Conference put forth a programme of colonial expansion in both Africa and Eastern Europe, which created a major storm abroad. Speaking to the Burgermeister of Hamburg in 1933, Hitler commented that Germany required several years of peace before it could be sufficiently rearmed enough to risk a war, and until then a policy of caution was called for. In his "peace speeches" of 17 May 1933, 21 May 1935, and 7 March 1936, Hitler stressed his supposed pacific goals and a willingness to work within the international system. In private, Hitler's plans were something less than pacific. At the first meeting of his Cabinet in 1933, Hitler placed military spending ahead of unemployment relief, and indeed was only prepared to spend money on the latter if the former was satisfied first. When the president of the Reichsbank, the former Chancellor Dr.Hans Luther, offered the new government the legal limit of 100 million Reichmarks to finance rearmament, Hitler found the sum too low, and sacked Luther in March 1933 to replace him with Hjalmar Schacht, who during the next five years was to advance 12 billion Reichmarks worth of "Mefo-bills" to pay for rearmament.

A major initiative in Hitler's foreign policy in his early years was to create an alliance with Britain. In the 1920s, Hitler wrote that a future National Socialist foreign policy goal was "the destruction of Russia with the help of England." In May 1933, Alfred Rosenberg in his capacity as head of the Nazi Party's Aussenpolitisches Amt (Foreign Political Office) visited London as part of a disastrous effort to win an alliance with Britain. In October 1933, Hitler pulled Germany out of both the League of Nations and World Disarmament Conference after his Foreign Minister Baron Konstantin von Neurath made it appear to world public opinion that the French demand for sécurité was the principal stumbling block.

In line with the views he advocated in Mein Kampf and Zweites Buch about the necessity of building an Anglo-German alliance, Hitler, in a meeting in November 1933 with the British Ambassador, Sir Eric Phipps, offered a scheme in which Britain would support a 300,000-strong German Army in exchange for a German "guarantee" of the British Empire. In response, the British stated a 10-year waiting period would be necessary before Britain would support an increase in the size of the German Army. A more successful initiative in foreign policy occurred with relations with Poland. In spite of intense opposition from the military and the Auswärtiges Amt who preferred closer ties with the Soviet Union, Hitler, in the fall of 1933 opened secret talks with Poland that were to lead to the German–Polish Non-Aggression Pact of January 1934.

In February 1934, Hitler met with the British Lord Privy Seal, Sir Anthony Eden, and hinted strongly that Germany already possessed an Air Force, which had been forbidden by the Treaty of Versailles. In the fall of 1934, Hitler was seriously concerned over the dangers of inflation damaging his popularity. In a secret speech given before his Cabinet on 5 November 1934, Hitler stated he had "given the working class his word that he would allow no price increases. Wage-earners would accuse him of breaking his word if he did not act against the rising prices. Revolutionary conditions among the people would be the further consequence."

Although a secret German armaments programme had been on-going since 1919, in March 1935, Hitler rejected Part V of the Versailles treaty by publicly announcing that the German army would be expanded to 600,000 men (six times the number stipulated in the Treaty of Versailles), introducing an Air Force (Luftwaffe) and increasing the size of the Navy (Kriegsmarine). Britain, France, Italy and the League of Nations quickly condemned these actions. However, after re-assurances from Hitler that Germany was only interested in peace, no country took any action to stop this development and German re-armament continued. Later in March 1935, Hitler held a series of meetings in Berlin with the British Foreign Secretary Sir John Simon and Eden, during which he successfully evaded British offers for German participation in a regional security pact meant to serve as an Eastern European equivalent of the Locarno pact while the two British ministers avoided taking up Hitler's offers of alliance. During his talks with Simon and Eden, Hitler first used what he regarded as the brilliant colonial negotiating tactic, when Hitler parlayed an offer from Simon to return to the League of Nations by demanding the return of the former German colonies in Africa.

Starting in April 1935, disenchantment with how the Third Reich had developed in practice as opposed to what had been promised led many in the Nazi Party, especially the Alte Kämpfer (Old Fighters; i.e., those who joined the Party before 1930, and who tended to be the most ardent anti-Semitics in the Party), and the SA into lashing out against Germany's Jewish minority as a way of expressing their frustrations against a group that the authorities would not generally protect. The rank and file of the Party were most unhappy that two years into the Third Reich, and despite countless promises by Hitler prior to 1933, no law had been passed banning marriage or sex between those Germans belonging to the "Aryan" and Jewish "races". A Gestapo report from the spring of 1935 stated that the rank and file of the Nazi Party would "set in motion by us from below," a solution to the "Jewish problem," "that the government would then have to follow." As a result, Nazi Party activists and the SA started a major wave of assaults, vandalism and boycotts against German Jews.

On 18 June 1935, the Anglo-German Naval Agreement (AGNA) was signed in London which allowed for increasing the allowed German tonnage up to 35% of that of the British navy. Hitler called the signing of the AGNA "the happiest day of his life" as he believed the agreement marked the beginning of the Anglo-German alliance he had predicted in Mein Kampf. This agreement was made without consulting either France or Italy, directly undermined the League of Nations and put the Treaty of Versailles on the path towards irrelevance. After the signing of the A.G.N.A., in June 1935 Hitler ordered the next step in the creation of an Anglo-German alliance: taking all the societies demanding the restoration of the former German African colonies and coordinating (Gleichschaltung) them into a new Reich Colonial League (Reichskolonialbund) which over the next few years waged an extremely aggressive propaganda campaign for colonial restoration. Hitler had no real interest in the former German African colonies. In Mein Kampf, Hitler had excoriated the Imperial German government for pursuing colonial expansion in Africa prior to 1914 on the grounds that the natural area for Lebensraum was Eastern Europe, not Africa. It was Hitler's intention to use colonial demands as a negotiating tactic that would see a German "renunciation" of colonial claims in exchange for Britain making an alliance with the Reich on German terms.

In the summer of 1935, Hitler was informed that, between inflation and the need to use foreign exchange to buy raw materials Germany lacked for rearmament, there were only 5 million Reichmarks available for military expenditure, and a pressing need for some 300,000 Reichmarks per day to prevent food shortages. In August 1935, Dr. Hjalmar Schacht advised Hitler that the wave of anti-Semitic violence was interfering with the workings of the economy, and hence rearmament. Following Dr. Schacht's complaints, plus reports that the German public did not approve of the wave of anti-Semitic violence, and that continuing police toleration of the violence was hurting the regime's popularity with the wider public, Hitler ordered a stop to "individual actions" against German Jews on 8 August 1935. From Hitler's perspective, it was imperative to bring in harsh new anti-Semitic laws as a consolation prize for those Party members who were disappointed with Hitler's halt order of 8 August, especially because Hitler had only reluctantly given the halt order for pragmatic reasons, and his sympathies were with the Party radicals. The annual Nazi Party Rally held at Nuremberg in September 1935 was to feature the first session of the Reichstag held at that city since 1543. Hitler had planned to have the Reichstag pass a law making the Nazi Swastika flag the flag of the German Reich, and a major speech in support of the impending Italian aggression against Ethiopia. Hitler felt that the Italian aggression opened great opportunities for Germany. In August 1935, Hitler told Goebbels his foreign policy vision as: "With England eternal alliance. Good relationship with Poland . . . Expansion to the East. The Baltic belongs to us . . . Conflicts Italy-Abyssinia-England, then Japan-Russia imminent."

At the last minute before the Nuremberg Party Rally was due to begin, the German Foreign Minister Baron Konstantin von Neurath persuaded Hitler to cancel his speech praising Italy for her willingness to commit aggression. Neurath convinced Hitler that his speech was too provocative to public opinion abroad as it contradicted the message of Hitler's "peace speeches", thus leaving Hitler with the sudden need to have something else to address the first meeting of the Reichstag in Nuremberg since 1543, other than the Reich Flag Law. On 13 September 1935, Hitler hurriedly ordered two civil servants, Dr. Bernhard Lösener and Franz Albrecht Medicus of the Interior Ministry to fly to Nuremberg to start drafting anti-Semitic laws for Hitler to present to the Reichstag for 15 September. On the evening of 15 September, Hitler presented two laws before the Reichstag banning sex and marriage between Aryan and Jewish Germans, the employment of Aryan women under the age of 45 in Jewish households, and deprived "non-Aryans" of the benefits of German citizenship. The laws of September 1935 are generally known as the Nuremberg Laws.

In October 1935, in order to prevent further food shortages and the introduction of rationing, Hitler reluctantly ordered cuts in military spending. In the spring of 1936 in response to requests from Richard Walther Darré, Hitler ordered 60 million Reichmarks of foreign exchange to be used to buy seed oil for German farmers, a decision that led to bitter complaints from Dr. Schacht and the War Minister Field Marshal Werner von Blomberg that it would be impossible to achieve rearmament as long as foreign exchange was diverted to preventing food shortages. Given the economic problems which was affecting his popularity by early 1936, Hitler felt the pressing need for a foreign policy triumph as a way of distracting public attention from the economy.

In an interview with the French journalist Bertrand de Jouvenel in February 1936, Hitler appeared to disavow Mein Kampf by saying that parts of his book were now out of date and he was not guided by them, though precisely which parts were out of date was left unclear. In March 1936, Hitler again violated the Versailles treaty by reoccupying the demilitarized zone in the Rhineland. When Britain and France did nothing, he grew bolder. In July 1936, the Spanish Civil War began when the military, led by General Francisco Franco, rebelled against the elected Popular Front government. After receiving an appeal for help from General Franco in July 1936, Hitler sent troops to support Franco, and Spain served as a testing ground for Germany's new forces and their methods. At the same time, Hitler continued with his efforts to create an Anglo-German alliance. In July 1936, he offered to Phipps a promise that if Britain were to sign an alliance with the Reich, then Germany would commit to sending twelve divisions to the Far East to protect British colonial possessions there from a Japanese attack. Hitler's offer was refused.

In August 1936, in response to a growing crisis in the German economy caused by the strains of rearmament, Hitler issued the "Four-Year Plan Memorandum" ordering Hermann Göring to carry out the Four Year Plan to have the German economy ready for war within the next four years. During the 1936 economic crisis, the German government was divided into two factions, with one (the so-called "free market" faction) centring around the Reichsbank President Hjalmar Schacht and the former Price Commissioner Dr. Carl Friedrich Goerdeler calling for decreased military spending and a turn away from autarkic policies, and another faction around Göring calling for the opposite. Supporting the "free-market" faction were some of Germany's leading business executives, most notably Hermann Duecher of AEG, Robert Bosch of Robert Bosch GmbH, and Albert Voegeler of Vereinigte Stahlwerke AG. Hitler hesitated for the first half of 1936 before siding with the more radical faction in his "Four Year Plan" memo of August. Historians such as Richard Overy have argued that the importance of the memo, which was written personally by Hitler, can be gauged by the fact that Hitler, who had something of a phobia about writing, hardly ever wrote anything down, which indicates that Hitler had something especially important to say. The "Four-Year Plan Memorandum" predicated an imminent all-out, apocalyptic struggle between "Judo-Bolshevism" and German National Socialism, which necessitated a total effort at rearmament regardless of the economic costs. In the memo, Hitler wrote:

Since the outbreak of the French Revolution, the world has been moving with ever increasing speed toward a new conflict, the most extreme solution of which is called Bolshevism, whose essence and aim, however, are solely the elimination of those strata of mankind which have hitherto provided the leadership and their replacement by worldwide Jewry. No state will be able to withdraw or even remain at a distance from this historical conflict . . . It is not the aim of this memorandum to prophesy the time when the untenable situation in Europe will become an open crisis. I only want, in these lines, to set down my conviction that this crisis cannot and will not fail to arrive and that it is Germany's duty to secure her own existence by every means in face of this catastrophe, and to protect herself against it, and that from this compulsion there arises a series of conclusions relating to the most important tasks that our people have ever been set. For a victory of Bolshevism over Germany would not lead to a Versailles treaty, but to the final destruction, indeed the annihilation of the German people . . . I consider it necessary for the Reichstag to pass the following two laws: 1) A law providing the death penalty for economic sabotage and 2) A law making the whole of Jewry liable for all damage inflicted by individual specimens of this community of criminals upon the German economy, and thus upon the German people.

Hitler called for Germany to have the world's "first army" in terms of fighting power within the next four years and that "the extent of the military development of our resources cannot be too large, nor its pace too swift" (italics in the original) and the role of the economy was simply to support "Germany's self-assertion and the extension of her Lebensraum." Hitler went on to write that given the magnitude of the coming struggle that the concerns expressed by members of the "free market" faction like Schacht and Goerdeler that the current level of military spending was bankrupting Germany were irrelevant. Hitler wrote that: "However well balanced the general pattern of a nation's life ought to be, there must at particular times be certain disturbances of the balance at the expense of other less vital tasks. If we do not succeed in bringing the German army as rapidly as possible to the rank of premier army in the world . . . then Germany will be lost!" and "The nation does not live for the economy, for economic leaders, or for economic or financial theories; on the contrary, it is finance and the economy, economic leaders and theories, which all owe unqualified service in this struggle for the self-assertion of our nation." Documents such as the Four Year Plan Memo have often been used by right historians such as Henry Ashby Turner and Karl Dietrich Bracher who argue for a "primacy of politics" approach (that Hitler was not subordinate to German business, but rather the contrary was the case) against the "primacy of economics" approach championed by Marxist historians (that Hitler was a "agent" of and subordinate to German business).

In August 1936, the freelance Nazi diplomat Joachim von Ribbentrop was appointed German Ambassador to the Embassy of Germany in London at the Court of St. James's. Before Ribbentrop left to take up his post in October 1936, Hitler told him: "Ribbentrop . . . get Britain to join the Anti-Comintern Pact, that is what I want most of all. I have sent you as the best man I've got. Do what you can . . . But if in future all our efforts are still in vain, fair enough, then I'm ready for war as well. I would regret it very much, but if it has to be, there it is. But I think it would be a short war and the moment it is over, I will then be ready at any time to offer the British an honourable peace acceptable to both sides. However, I would then demand that Britain join the Anti-Comintern Pact or perhaps some other pact. But get on with it, Ribbentrop, you have the trumps in your hand, play them well. I'm ready at any time for an air pact as well. Do your best. I will follow your efforts with interest".

An Axis was declared between Germany and Italy by Count Galeazzo Ciano, foreign minister of Fascist dictator Benito Mussolini, on 25 October 1936. On 25 November of the same year, Germany concluded the Anti-Comintern Pact with Japan. At the time of the signing of the Anti-Comintern Pact, invitations were sent out for Britain, China, Italy and Poland to adhere; of the invited powers only the Italians were to sign the pact, in November 1937. To strengthen relationship with Japan, Hitler met in 1937 in Nuremberg Prince Chichibu, a brother of emperor Hirohito. However, the meeting with Prince Chichibu had little consequence, as Hitler refused the Japanese request to halt German arms shipments to China or withdraw the German officers serving with the Chinese in the Second Sino-Japanese War. Both the military and the Auswärtiges Amt (Foreign Office) were strongly opposed to ending the informal German alliance with China that existed since the 1910s, and pressured Hitler to avoid offending the Chinese. TheAuswärtiges Amt and the military both argued to Hitler that given the foreign exchange problems which afflicted German rearmament, and the fact that various Sino-German economic agreements provided Germany with raw materials that would otherwise use up precious foreign exchange, it was folly to seek an alliance with Japan that would have the inevitable result of ending the Sino-German alignment.

By the latter half of 1937, Hitler had abandoned his dream of an Anglo-German alliance, blaming "inadequate" British leadership for turning down his offers of an alliance. In a talk with the League of Nations High Commissioner for the Free City of Danzig, the Swiss diplomat Carl Jacob Burckhardt in September 1937, Hitler protested what he regarded as British interference in the "German sphere" in Europe, though in the same talk, Hitler made clear his view of Britain as an ideal ally, which for pure selfishness was blocking German plans.

Hitler had suffered severely from stomach pains and eczema in 1936–37, leading to his remark to the Nazi Party's propaganda leadership in October 1937 that because both parents died early in their lives, he would probably follow suit, leaving him with only a few years to obtain the necessary Lebensraum. About the same time, Dr. Goebbels noted in his diary Hitler now wished to see the "Great Germanic Reich" he envisioned in his own lifetime rather than leaving the work of building the "Great Germanic Reich" to his successors.

On 5 November 1937, at the Reich Chancellory, Adolf Hitler held a secret meeting with the War and Foreign Ministers and the three service chiefs, recorded in the Hossbach Memorandum, and stated his intentions for acquiring "living space" Lebensraum for the German people. He ordered the attendees to make plans for war in the east no later than 1943 in order to acquire Lebensraum. Hitler stated the conference minutes were to be regarded as his "political testament" in the event of his death. In the memo, Hitler was recorded as saying that such a state of crisis had been reached in the German economy that the only way of stopping a severe decline in living standards in Germany was to embark sometime in the near-future on a policy of aggression by seizing Austria and Czechoslovakia. Moreover, Hitler stated that the arms race meant that time for action had to occur before Britain and France obtained a permanent lead in the arms race. A striking change in the Hossbach Memo was Hitler's changed view of Britain from the prospective ally of 1928 in the Zweites Buch to the "hate-inspired antagonist" of 1937 in the Hossbach memo. The historian Klaus Hildebrand described the memo as the start of an "ambivalent course" towards Britain while the late historian Andreas Hillgruber argued that Hitler was embarking on expansion "without Britain," preferably "with Britain," but if necessary "against Britain."

Hitler's intentions outlined in the Hossbach memorandum led to strong protests from the Foreign Minister, Baron Konstantin von Neurath, the War Minister Field Marshal Werner von Blomberg, and the Army Commander General Werner von Fritsch, that any German aggression in Eastern Europe was bound to trigger a war with France because of the French alliance system in Eastern Europe (the so-called cordon sanitaire), and if a Franco-German war broke out, then Britain was almost certain to intervene rather than risk the chance of a French defeat. The aggression against Austria and Czechoslovakia were intended to be the first of a series of localized wars in Eastern Europe that would secure Germany's position in Europe before the final showdown with Britain and France. Fritsch, Blomberg and Neurath all argue that Hitler was pursuing an extremely high-risk strategy of localized wars in Eastern Europe that was most likely to cause a general war before Germany was ready for such a conflict, and advised Hitler to wait until Germany had more time to rearm. Neurath, Blomberg and Fritsch had no moral objections to German aggression, but rather based their opposition on the question of timing – determining the best time for aggression.

Late in November 1937, Hitler received as his guest the British Lord Privy Seal, Lord Halifax who was visiting Germany ostensibly as part of a hunting trip. Speaking of changes to Germany's frontiers, Halifax told Hitler that: "All other questions fall into the category of possible alterations in the European order which might be destined to come about with the passage of time. Amongst these questions were Danzig, Austria and Czechoslovakia. England was interested to see that any alterations should come through the course of peaceful evolution and that the methods should be avoided which might cause far-reaching disturbances." Significantly, Halifax made clear in his statements to Hitler — though whether Hitler appreciated the significance of this or not is unclear — that any possible territorial changes had to be accomplished peacefully, and that though Britain had no security commitments in Eastern Europe beyond the Covenant of the League of Nations, would not tolerate territorial changes via war. Hitler seems to have misunderstood Halifax's remarks as confirming his conviction that Britain would just stand aside while he pursued his strategy of limited wars in Eastern Europe.

Hitler was most unhappy with the criticism of his intentions expressed by Neurath, Blomberg, and Fritsch in the Hossbach Memo, and in early 1938 asserted his control of the military-foreign policy apparatus through the Blomberg-Fritsch Affair, the abolition of the War Ministry and its replacement by the OKW, and by sacking Neurath as Foreign Minister on 4 February 1938, assuming the rank, role and tile of the Oberster Befehlshaber der Wehrmacht (supreme commander of the armed forces). The British economic historian Richard Overy commented that the establishment of the OKW in February 1938 was a clear sign of what Hitler's intentions were since supreme headquarters organizations such as the OKW are normally set up during wartime, not peacetime. The Official German history of World War II has argued that from early 1938 onwards, Hitler was not carrying out a foreign policy that had carried a high risk of war, but was carrying out a foreign policy aiming at war.

One of the foundations of Hitler's social policies was the concept of racial hygiene. It was based on the ideas of Arthur de Gobineau, a French count; eugenics, a pseudo-science that advocated racial purity; and social Darwinism. Applied to human beings, "survival of the fittest" was interpreted as requiring racial purity and killing off "life unworthy of life." The first victims were children with physical and developmental disabilities; those killings occurred in a programme dubbed Action T4. After a public outcry, Hitler made a show of ending this program, but the killings in fact continued. Between 1939 and 1945, the SS, assisted by collaborationist governments and recruits from occupied countries, systematically killed somewhere between 11 and 14 million people, including about six million Jews, in concentration camps, ghettos and mass executions, or through less systematic methods elsewhere. In addition to those gassed to death, many died as a result of starvation and disease while working as slave labourers (sometimes benefiting private German companies). Along with Jews, non-Jewish Poles, Communists and political opponents, members of resistance groups, homosexuals, Roma, the physically handicapped and mentally retarded, Soviet prisoners of war (possibly as many as three million), Jehovah's Witnesses, Adventists, trade unionists, and psychiatric patients were killed. One of the biggest centres of mass-killing was the industrial extermination camp complex of Auschwitz-Birkenau. As far as is known, Hitler never visited the concentration camps and did not speak publicly about the killing in precise terms.

The Holocaust (the "Endlösung der jüdischen Frage" or "Final Solution of the Jewish Question") was planned and ordered by leading Nazis, with Heinrich Himmler and Reinhard Heydrich playing key roles. While no specific order from Hitler authorizing the mass killing has surfaced, there is documentation showing that he approved the Einsatzgruppen killing squads that followed the German army through Poland and Russia, and that he was kept well informed about their activities. The evidence also suggests that in the fall of 1941 Himmler and Hitler decided upon mass extermination by gassing. During interrogations by Soviet intelligence officers declassified over fifty years later, Hitler's valet Heinz Linge and his military aide Otto Gunsche said Hitler had "pored over the first blueprints of gas chambers." His private secretary, Traudl Junge, testified that Hitler knew all about the death camps. Göring gave a written authorisation to Heydrich to "make all necessary preparations" for a "total solution of the Jewish question". To make for smoother cooperation in the implementation of this "Final Solution", the Wannsee conference was held on 20 January 1942, with fifteen senior officials participating (including Adolf Eichmann) and led by Reinhard Heydrich. The records of this meeting provide the clearest evidence of planning for the Holocaust. On 22 February, Hitler was recorded saying to his associates, "we shall regain our health only by eliminating the Jews".

In February 1938, Hitler finally ended the dilemma that had plagued German Far Eastern policy, namely whether to continue the informal Sino-German alliance that existed with the Republic of China since the 1910s or to create a new alliance with Japan. The military at the time strongly favoured continuing Germany's alliance with China. China had the support of Foreign Minister Konstantin von Neurath and War Minister Werner von Blomberg, the so-called "China Lobby" who tried to steer German foreign policy away from war in Europe. Both men, however, were sacked by Hitler in early 1938. Upon the advice of Hitler's newly appointed Foreign Minister, the strongly pro-Japanese Joachim von Ribbentrop, Hitler chose to end the alliance with China as the price of gaining an alignment with the more modern and powerful Japan. In an address to the Reichstag, Hitler announced German recognition of Manchukuo, the Japanese occupied puppet state in Manchuria, and renounced the German claims to the former colonies in the Pacific held by Japan. Hitler ordered an end to arms shipments to China, and ordered the recall of all the German officers attached to the Chinese Army. In retaliation for ending German support to China in the war against Japan, Chinese Generalissimo Chiang Kai-shek canceled all of the Sino-German economic agreements, which deprived the Germans of raw materials such as tungsten that the Chinese had previously provided. The ending of the Sino-German alignment increased the problems of German rearmament, as the Germans were now forced to use their limited supply of foreign exchange to buy raw materials on the open market.

In March 1938, Hitler pressured Austria into unification with Germany (the Anschluss) and made a triumphant entry into Vienna on 14 March. Next, he intensified a crisis over the German-speaking Sudetenland districts of Czechoslovakia.

On 3 March 1938, the British Ambassador Sir Neville Henderson met with Hitler and presented on behalf of his government a proposal for an international consortium to rule much of Africa (in which Germany would be assigned a leading role) in exchange for a German promise never to resort to war to change the frontiers. Hitler, who was more interested in Lebensraum in Eastern Europe than in participating in international consortiums, rejected the British offer, using as his excuse that he wanted the former German African colonies returned to the Reich, not an international consortium running Central Africa. Moreover, Hitler argued that it was totally outrageous on Britain's part to impose conditions on German conduct in Europe as the price for territory in Africa. Hitler ended the conversation by telling Henderson he would rather wait 20 years for the return of the former colonies than accept British conditions for avoiding war.

On 28–29 March 1938, Hitler held a series of secret meetings in Berlin with Konrad Henlein of the Sudeten Heimfront (Home Front), the largest of the ethnic German parties of the Sudetenland. During the Hitler-Henlein meetings, it was agreed that Henlein would provide the pretext for German aggression against Czechoslovakia by making demands on Prague for increased autonomy for Sudeten Germans that Prague could never be reasonably expected to fulfill. In April 1938, Henlein told the foreign minister of Hungary that "whatever the Czech government might offer, he would always raise still higher demands ... he wanted to sabotage an understanding by all means because this was the only method to blow up Czechoslovakia quickly". In private, Hitler considered the Sudeten issue unimportant; his real intentions being to use the Sudeten question as the justification both at home and abroad for a war of aggression to destroy Czechoslovakia, under the grounds of self-determination, and Prague's refusal to meet Henlein's demands. Hitler's plans called for a massive military build-up along the Czechoslovak border, relentless propaganda attacks about the supposed ill treatment of the Sudetenlanders, and finally, "incidents" between Heimfront activists and the Czechoslovak authorities to justify an invasion that would swiftly destroy Czechoslovakia in a few days campaign before other powers could act. Since Hitler wished to have the fall harvest brought in as much as possible, and to complete the so-called "West Wall" to guard the Rhineland, the date for the invasion was chosen for late September or early October 1938.

In April 1938, Hitler ordered the OKW to start preparing plans for Fall Grün (Case Green), the codename for an invasion of Czechoslovakia. Further increasing the tension in Europe was the May Crisis of 19–22 May 1938. The May Crisis of 1938 was a false alarm caused by rumours that Czechoslovakia would be invaded the weekend of the municipal elections in that country, erroneous reports of major German troop movements along the Czechoslovak border just prior to the elections, the killing of two ethnic Germans by the Czechoslovak police, and Ribbentrop's highly bellicose remarks to Henderson when the latter asked the former if an invasion was indeed scheduled for the weekend, which led to a partial Czechoslovak mobilization and firm warnings from London against a German move against Czechoslovakia before it was realized that no invasion was intended for that weekend. Though no invasion had been planned for May 1938, it was believed in London that such a course of action was indeed being considered in Berlin, leading to two warnings on 21 May and 22 May that the United Kingdom would go to war with Germany if France became involved in a war with Germany. Hitler, for his part, was, to use the words of an aide, highly "furious" with the perception that he had been forced to back down by the Czechoslovak mobilization and the warnings from London and Paris, when he had, in fact, been planning nothing for that weekend. Though plans had already been drafted in April 1938 for an invasion of Czechoslovakia in the near future, the May Crisis and the perception of a diplomatic defeat further reinforced Hitler in his chosen course. The May Crisis seemed to have had the effect of convincing Hitler that expansion "without Britain" was not possible, and expansion "against Britain" was the only viable course. In the immediate aftermath of the May crisis, Hitler ordered an acceleration of German naval building beyond the limits of the A.G.N.A., and in the "Heye memorandum", drawn at Hitler's orders, envisaged the Royal Navy for the first time as the principal opponent of the Kriegsmarine.

At the conference of 28 May 1938, Hitler declared that it was his "unalterable" decision to "smash Czechoslovakia" by 1 October of the same year, which was explained as securing the eastern flank "for advancing against the West, England and France". At the same conference, Hitler expressed his belief that Britain would not risk a war until British rearmament was complete, which Hitler felt would be around 1941–42, and Germany should in a series of wars eliminate France and her allies in Europe in the interval in the years 1938–41 while German rearmament was still ahead. Hitler's determination to go through with Fall Grün in 1938 provoked a major crisis in the German command structure. The Chief of the General Staff, General Ludwig Beck, protested in a lengthy series of memos that Fall Grün would start a world war that Germany would lose, and urged Hitler to put off the projected war. Hitler called Beck's arguments against war "kindische Kräfteberechnungen" ("childish power play calculations").

On 4 August 1938, a secret Army meeting was held at which Beck read his report. They agreed something had to be done to prevent certain disaster. Beck hoped they would all resign together but no one resigned except Beck. However his replacement, General Franz Halder, sympathised with Beck and together they conspired with several top generals, Admiral Wilhelm Canaris (Chief of German Intelligence) and Graf von Helldorf (Berlin's Police Chief), to arrest Hitler the moment he gave the invasion order. However, the plan would only work if both Britain and France made it known to the world that they would fight to preserve Czechoslovakia. This would help to convince the German people that certain defeat awaited Germany. Agents were therefore sent to England to tell Chamberlain that an attack on Czechoslovakia was planned and their intentions to overthrow Hitler if this occurred. However the messengers were not taken seriously by the British. In September, Chamberlain and French Premier Édouard Daladier decided not to threaten a war over Czechoslovakia and so the planned removal of Hitler could not be justified. The Munich Agreement therefore preserved Hitler in power.

Starting in August 1938, information reached London that Germany was beginning to mobilize reservists, together with information leaked by anti-war elements in the German military that the war was scheduled for sometime in September. Finally, as a result of intense French, and especially British diplomatic pressure, President Edvard Beneš unveiled on 5 September 1938, the "Fourth Plan" for constitutional reorganization of his country, which granted most of the demands for Sudeten autonomy made by Henlein in his Karlsbad speech of April 1938, and threatened to deprive the Germans of their pretext for aggression. Henlein's Heimfront promptly responded to the offer of "Fourth Plan" by having a series of violent clashes with the Czechoslovak police, culminating in major clashes in mid September that led to the declaration of martial law in certain Sudeten districts. In a response to the threatening situation, in late August 1938, the British Prime Minister Neville Chamberlain had conceived of Plan Z, namely to fly to Germany, meet Hitler, and then work out an agreement that could end the crisis. On 13 September 1938, Chamberlain offered to fly to Germany to discuss a solution to the crisis. Chamberlain had decided to execute Plan Z in response to erroneous information supplied by the German opposition that the invasion was due to start any time after 18 September. Though Hitler was not happy with Chamberlain's offer, he agreed to see the British Prime Minister because to refuse Chamberlain's offer would confirm the lie to his repeated claims that he was a man of peace driven reluctantly to war because of Beneš's intractability. In a summit at Berchtesgaden, Chamberlain promised to pressure Beneš into agreeing to Hitler's publicly stated demands about allowing the Sudetenland to join Germany, in return for a reluctant promise by Hitler to postpone any military action until Chamberlain had given a chance to fulfill his promise. Hitler had agreed to the postponement out of the expectation that Chamberlain would fail to secure Prague's consent to transferring the Sudetenland, and was, by all accounts, most disappointed when Franco-British pressure secured just that. The talks between Chamberlain and Hitler in September 1938 were made difficult by their innately differing concepts of what Europe should look like, with Hitler aiming to use the Sudeten issue as a pretext for war and Chamberlain genuinely striving for a peaceful solution.

When Chamberlain returned to Germany on 22 September to present his peace plan for the transfer of the Sudetenland at a summit with Hitler at Bad Godesberg, the British delegation was most unpleasantly surprised to have Hitler reject his own terms he had presented at Berchtesgaden as now unacceptable. To put an end to Chamberlain's peace-making efforts once and for all, Hitler demanded the Sudetenland be ceded to Germany no later than 28 September 1938 with no negotiations between Prague and Berlin and no international commission to oversee the transfer; no plebiscites to be held in the transferred districts until after the transfer; and for good measure, that Germany would not forsake war as an option until all the claims against Czechoslovakia by Poland and Hungary had been satisfied. The differing views between the two leaders were best symbolized when Chamberlain was presented with Hitler's new demands and protested at being presented with an ultimatum, leading Hitler in turn to retort that because his document stating his new demands was entitled "Memorandum", it could not possibly be an ultimatum. On 25 September 1938 Britain rejected the Bad Godesberg ultimatum, and began preparations for war. To further underline the point, Sir Horace Wilson, the British government's Chief Industrial Advisor, and a close associate of Chamberlain, was dispatched to Berlin to inform Hitler that if the Germans attacked Czechoslovakia, then France would honour her commitments as demanded by the Franco-Czechoslovak alliance of 1924, and "then England would feel honour bound, to offer France assistance". Initially, determined to continue with attack planned for 1 October 1938, sometime between 27 and 28 September, Hitler changed his mind, and asked to take up a suggestion, of and through the intercession of Mussolini, for a conference to be held in Munich with Chamberlain, Mussolini, and Daladier to discuss the Czechoslovak situation. Just what had caused Hitler to change his attitude is not entirely clear, but it is likely that the combination of Franco-British warnings, and especially the mobilization of the British fleet, had finally convinced him of what the most likely result of Fall Grün would be; the minor nature of the alleged casus belli being the timetables for the transfer made Hitler appear too much like the aggressor; the view from his advisors that Germany was not prepared either militarily or economically for a world war; warnings from the states that Hitler saw as his would-be allies in the form of Italy, Japan, Poland and Hungary that they would not fight on behalf of Germany; and very visible signs that the majority of Germans were not enthusiastic about the prospect of war. Moreover, Germany lacked sufficient supplies of oil and other crucial raw materials (the plants that would produce the synthetic oil for the German war effort were not in operation yet), and was highly dependent upon imports from abroad. The Kriegsmarine reported that should war come with Britain, it could not break a British blockade, and since Germany had hardly any oil stocks, Germany would be defeated for no other reason than a shortage of oil. The Economics Ministry told Hitler that Germany had only 2.6 million tons of oil at hand, and should war with Britain and France, would require 7.6 million tons of oil. Starting on 18 September 1938, the British refused to supply metals to Germany, and on 24 September the Admiralty forbade British ships to sail to Germany. The British detained the tanker Invershannon carrying 8,600 tons of oil to Hamburg, which caused immediate economic pain in Germany. Given Germany's dependence on imported oil (80% of German oil in the 1930s came from the New World), and the likelihood that a war with Britain would see a blockade cutting Germany off from oil supplies, historians have argued that Hitler's decision to see a peaceful end to call off Fall Grün was due to concerns about the oil problem.

On 30 September 1938, a one-day conference was held in Munich attended by Hitler, Chamberlain, Daladier and Mussolini that led to the Munich Agreement, which gave in to Hitler's ostensible demands by handing over the Sudetenland districts to Germany. Since London and Paris had already agreed to the idea of a transfer of the disputed territory in mid-September, the Munich Conference mostly comprised discussions in one day of talks on technical questions about how the transfer of the Sudetenland would take place, and featured the relatively minor concessions from Hitler that the transfer would take place over a ten day period in October, overseen by an international commission, and Germany would wait until Hungarian and Polish claims were settled. At the end of the conference, Chamberlain had Hitler sign a declaration of Anglo-German friendship, to which Chamberlain attached great importance and Hitler none at all. Though Chamberlain was well-satisfied with the Munich conference, leading to his infamous claim to have secured "peace for our time", Hitler was privately furious about being "cheated" out of the war he was desperate to have in 1938. As a result of the summit, Hitler was TIME magazine's Man of the Year for 1938.

By appeasing Hitler, Britain and France left Czechoslovakia to Hitler's mercy. Though Hitler professed happiness in public over the achievement of his ostensible demands, in private he was determined to have a war the next time around by ensuring that Germany's future demands would not be met. In Hitler's view, a British-brokered peace, though extremely favourable to the ostensible German demands, was a diplomatic defeat which proved that Britain needed to be ended as a power to allow him to pursue his dreams of eastern expansion. In the aftermath of Munich, Hitler felt since Britain would not ally herself nor stand aside to facilitate Germany's continental ambitions, it had become a major threat, and accordingly, Britain replaced the Soviet Union in Hitler's mind as the main enemy of the Reich, with German policies being accordingly reoriented. Hitler expressed his disappointment over the Munich Agreement in a speech on 9 October 1938 in Saarbrücken when he lashed out against the Conservative anti-appeasers Winston Churchill, Alfred Duff Cooper and Anthony Eden, whom Hitler described as a warmongering anti-German fraction, who would attack Germany at the first opportunity, and were likely to come to power at any moment.

In the same speech, Hitler claimed "We Germans will no longer endure such governessy interference. Britain should mind her own business and worry about her own troubles". In November 1938, Hitler ordered a major anti-British propaganda campaign to be launched with the British being loudly abused for their "hypocrisy" in maintaining world-wide empire while seeking to block the Germans from acquiring an empire of their own. A particular highlight in the anti-British propaganda was alleged British human rights abuses in dealing with the Arab uprising in the Palestine Mandate and in India, and the "hyprocrisy" of British criticism of the November 1938 Kristallnacht event. This marked a huge change from the earlier years of the Third Reich, when the German media had portrayed the British Empire in very favourable terms. In November 1938, the Foreign Minister Joachim von Ribbentrop was ordered to convert the Anti-Comintern Pact into an open anti-British military alliance, as a prelude for a war against Britain and France. On 27 January 1939, Hitler approved the Z Plan, a five-year naval expansion program which called for a Kriegsmarine of 10 battleships, four aircraft carriers, three battlecruisers, eight heavy cruisers, 44 light cruisers, 68 destroyers and 249 U-boats by 1944 that was intended to crush the Royal Navy. The importance of the Z Plan can be seen in Hitler's orders that henceforward the Kriegsmarine was to go from third to first in allotment of raw materials, money and skilled workers. In the spring of 1939, the Luftwaffe was ordered to start building a strategic bombing force that was meant to level British cities. Hitler's war plans against Britain called for a joint Kriegsmarine-Luftwaffe offensive that was to stage "rapid annihilating blows" against British cities and shipping with the expectation that "The moment England is cut off from her supplies she is forced to capitulate" as Hitler expected that the experience of living in a blockaded, famine-stricken, bombed-out island to be too much for the British public.

In November 1938, in a secret speech to a group of German journalists, Hitler noted that he had been forced to speak of peace as the goal in order to attain the degree of rearmament "which were an essential prerequisite ... for the next step". In the same speech, Hitler complained that his peace propaganda of the last five years had been too successful, and it was time for the German people to be subjected to war propaganda. Hitler stated: "It is self-evident that such peace propaganda conducted for a decade has its risky aspect; because it can too easily induce people to come to the conclusion that the present government is identical with the decision and with the intention to keep peace under all circumstances", and instead called for new journalism that "had to present certain foreign policy events in such a fashion that the inner voice of the people itself slowly begins to shout out for the use of force." Later in November 1938, Hitler expressed frustration with the more cautious advice he was receiving from some quarters. Hitler called the economic expert Carl Friedrich Goerdeler, General Ludwig Beck, Dr. Hjalmar Schacht, the diplomat Ulrich von Hassell, and the economist Rudolf Brinkmann "the overbred intellectual circles" who were trying to block him from fulfilling his mission by their appeals to caution, and but for the fact that he needed their skills "otherwise, perhaps we could someday exterminate them or do something of this kind to them".

In December 1938, the Chancellery of the Führer headed by Philipp Bouhler received a letter concerning a severely physically and mentally disabled baby girl named Sofia Knauer living in Leipzig. At that time, there was a furious rivalry existing between Bouhler's office, the office of the Reich Chancellery led by Hans-Heinrich Lammers, the Presidential Chancellery of Otto Meissner, the office of Hitler's adjutant Wilhelm Brückner and the Deputy Führer's office which was effectively headed by Martin Bormann over control over access to Hitler. As part of a power play against his rivals, Bouhler presented the letter concerning the disabled girl to Hitler, who thanked Bouhler for bringing the matter to his attention and responded by ordering his personal physician Dr. Karl Brandt to kill Knauer. In January 1939, Hitler ordered Bouhler and Dr. Brandt to henceforward have all disabled infants born in Germany killed. This was the origin of the Action T4 program. Subsequently Dr. Brandt and Bouhler, acting on their own initiative in the expectation of winning Hitler's favour, expanded the T4 program to killing, first, all physically or mentally disabled children in Germany, and, second, all disabled adults.

In late 1938 and early 1939, the continuing economic crisis caused by problems of rearmament, especially the shortage of foreign hard currencies needed to pay for raw materials Germany lacked, together with reports from Göring that the Four Year Plan was hopelessly behind schedule, forced Hitler in January 1939 to reluctantly order major defence cuts with the Wehrmacht having its steel allocations cut by 30%, aluminium 47%, cement 25%, rubber 14% and copper 20%. On 30 January 1939, Hitler made his "Export or die" speech calling for a German economic offensive ("export battle", to use Hitler's term), to increase German foreign exchange holdings to pay for raw materials such as high-grade iron needed for military materials. The "Export or die" speech of 30 January 1939 is also known as Hitler's "Prophecy Speech". The name which that speech is known comes from Hitler's "prophecy" issued towards the end of the speech:

"One thing I should like to say on this day which may be memorable for others as well for us Germans: In the course of my life I have very often been a prophet, and I have usually been ridiculed for it. During the time of my struggle for power it was in the first instance the Jewish race which only received my prophecies with laughter when I said I would one day take over the leadership of the State, and that of the whole nation, and that I would then among many other things settle the Jewish problem. Their laughter was uproarious, but I think that for some time now they have been laughing on the other side of the face. Today I will be once more the prophet. If the international Jewish financiers outside Europe should succeed in plunging the nations once more into a world war, then the result will not be the bolsheviszation of the earth, and thus the victory of Jewry, but the annihilation of the Jewish race in Europe!"

A significant historical debate has swung around the "Prophecy Speech". Historians who take an intentionist line such as Eberhard Jäckel have argued that at minimum from the time of the "Prophecy Speech" onwards, Hitler was committed to genocide of the Jews as his central goal. Lucy Dawidowicz and Gerald Fleming have argued that the "Prophecy Speech" was simply Hitler's way of saying that once he started a world war, he would use that war as a cover for his already pre-existing plans for genocide. Functionalist historians such as Christopher Browning have dismissed this interpretation under the grounds that if Hitler were serious with the intentions expressed in the "Prophecy Speech", then why the 30-month "stay of execution" between the outbreak of World War II in September 1939, and the opening of the first Vernichtungslager in late 1941. In addition, Browning has pointed to the existence of the Madagascar Plan of 1940–41 and various other schemes as proof that there was no genocidal master plan. In Browning's opinion, the "Prophecy Speech" was merely a manifestation of bravado on Hitler's part, and had little connection with actual unfolding of anti-Semitic policies.

At least part of the reason why Hitler violated the Munich Agreement by seizing the Czech half of Czechoslovakia in March 1939 was to obtain Czechoslovak assets to help with the economic crisis. Hitler ordered Germany's army to enter Prague on 15 March 1939, and from Prague Castle proclaimed Bohemia and Moravia a German protectorate.

As part of the anti-British course, it was deemed necessary by Hitler to have Poland either a satellite state or otherwise neutralized. Hitler believed this necessary both on strategic grounds as a way of securing the Reich's eastern flank and on economic grounds as a way of evading the effects of a British blockade. Initially, the German hope was to transform Poland into a satellite state, but by March 1939 the German demands had been rejected by the Poles three times, which led Hitler to decide upon the destruction of Poland as the main German foreign policy goal of 1939. On 3 April 1939, Hitler ordered the military to start preparing for Fall Weiss (Case White), the plan for a German invasion to be executed on 25 August 1939. In August 1939, Hitler spoke to his generals that his original plan for 1939 had to "... establish an acceptable relationship with Poland in order to fight against the West" but since the Poles would not co-operate in setting up an "acceptable relationship" (i.e. becoming a German satellite), he believed he had no choice other than wiping Poland off the map. The historian Gerhard Weinberg has argued since Hitler's audience comprised men who were all for the destruction of Poland (anti-Polish feelings were traditionally very strong in the German Army), but rather less happy about the prospect of war with Britain and France, if that was the price Germany had to pay for the destruction of Poland, it is quite likely that Hitler was speaking the truth on this occasion. In his private discussions with his officials in 1939, Hitler always described Britain as the main enemy that had to be defeated, and in his view, Poland's obliteration was the necessary prelude to that goal by securing the eastern flank and helpfully adding to Germany's Lebensraum. Hitler was much offended by the British "guarantee" of Polish independence issued on 31 March 1939, and told his associates that "I shall brew them a devil's drink". In a speech in Wilhelmshaven for the launch of the battleship Tirpitz on 1 April 1939, Hitler threatened to denounce the Anglo-German Naval Agreement if the British persisted with their "encirclement" policy as represented by the "guarantee" of Polish independence. As part of the new course, in a speech before the Reichstag on 28 April 1939, Adolf Hitler, complaining of British "encirclement" of Germany, renounced both the Anglo-German Naval Agreement and the German–Polish Non-Aggression Pact.

As a pretext for aggression against Poland, Hitler claimed the Free City of Danzig and the right for "extra-territorial" roads across the Polish Corridor which Germany had unwillingly ceded under the Versailles treaty. For Hitler, Danzig was just a pretext for aggression as the Sudetenland had been intended to be in 1938, and throughout 1939, while highlighting the Danzig issue as a grievance, the Germans always refused to engage in talks about the matter. A notable contradiction existed in Hitler's plans between the long-term anti-British course, whose major instruments such as a vastly expanded Kriegsmarine and Luftwaffe would take several years to complete, and Hitler's immediate foreign policy in 1939, which was likely to provoke a general war by engaging in such actions as attacking Poland. Hitler's dilemma between his short-term and long-term goals was resolved by Foreign Minister Joachim von Ribbentrop, who told Hitler that neither Britain nor France would honour their commitments to Poland, and any German–Polish war would accordingly be a limited regional war. Ribbentrop based his appraisal partly on an alleged statement made to him by the French Foreign Minister Georges Bonnet in December 1938 that France now recognized Eastern Europe as Germany's exclusive sphere of influence. In addition, Ribbentrop's status as the former Ambassador to London made him in Hitler's eyes the leading Nazi British expert, and as a result, Ribbentrop's advice that Britain would not honour her commitments to Poland carried much weight with Hitler. Ribbentrop only showed Hitler diplomatic cables that supported his analysis. In addition, the German Ambassador in London, Herbert von Dirksen, tended to send reports that supported Ribbentrop's analysis such as a dispatch in August 1939 that reported British Prime Minister Neville Chamberlain knew "the social structure of Britain, even the conception of the British Empire, would not survive the chaos of even a victorious war", and so would back down. The extent that Hitler was influenced by Ribbentrop's advice can be seen in Hitler's orders to the German military on 21 August 1939 for a limited mobilization against Poland alone. Hitler chose late August as his date for Fall Weiss in order to limit disruption to German agricultural production caused by mobilization. The problems caused by the need to begin a campaign in Poland in late August or early September in order to have the campaign finished before the October rains arrived, and the need to have sufficient time to concentrate German troops on the Polish border left Hitler in a self-imposed situation in August 1939 where Soviet co-operation was absolutely crucial if he were to have a war that year.

The Munich agreement appeared to be sufficient to dispel most of the remaining hold which the "collective security" idea may have had in Soviet circles, and, on 23 August 1939, Joseph Stalin accepted Hitler's proposal to conclude a non-aggression pact (the Molotov - Ribbentrop Pact), whose secret protocols contained an agreement to partition Poland. A major historical debate about the reasons for Hitler's foreign policy choices in 1939 concerns whether a structural economic crisis drove Hitler into a "flight into war" as claimed by the Marxist historian Timothy Mason or whether Hitler's actions were more influenced by non-economic factors as claimed by the economic historian Richard Overy. Historians such as William Carr, Gerhard Weinberg and Ian Kershaw have argued that a non-economic reason for Hitler's rush to war was Hitler's morbid and obsessive fear of an early death, and hence his feeling that he did not have long to accomplish his work. In the last days of peace, Hitler oscillated between the determination to fight the Western powers if he had to, and various schemes intended to keep Britain out of the war, but in any case, Hitler was not to be deterred from his aim of invading Poland. Only very briefly, when news of the Anglo-Polish alliance being signed on 25 August 1939 in response to the German-Soviet Non-Aggression Pact (instead of the severing of ties between London and Warsaw predicted by Ribbentrop) together with news from Italy that Mussolini would not honour the Pact of Steel, caused Hitler to postpone the attack on Poland from 25 August to 1 September. Hitler chose to spend the last days of peace either trying to manoeuvre the British into neutrality through his offer of 25 August 1939 to "guarantee" the British Empire, or having Ribbentrop present a last-minute peace plan to Henderson with an impossibly short time limit for its acceptance as part of an effort to blame the war on the British and Poles. On 1 September 1939, Germany invaded western Poland. Britain and France declared war on Germany on 3 September but did not immediately act. Hitler was most unpleasantly surprised at receiving the British declaration of war on 3 September 1939, and turning to Ribbentrop angrily asked "Now what?" Ribbentrop had nothing to say other than that Robert Coulondre, the French Ambassador, would probably be by later that day to present the French declaration of war. Not long after this, on 17 September, Soviet forces invaded eastern Poland.

After the fall of Poland came a period journalists called the "Phoney War," or Sitzkrieg ("sitting war"). In part of north-western Poland annexed to Germany, Hitler instructed the two Gauleiters in charge of the area, namely Albert Forster and Arthur Greiser, to "Germanize" the area, and promised them "There would be no questions asked" about how this "Germanization" was to be accomplished. Hitler's orders were interpreted in very different ways by Forster and Greiser. Forster followed a policy of simply having the local Poles sign forms stating they had German blood with no documentation required, whereas Greiser carried out a brutal ethnic cleansing campaign of expelling the entire Polish population into the Government-General of Poland. When Greiser, seconded by Himmler, complained to Hitler that Forster was allowing thousands of Poles to be accepted as "racial" Germans and thus "contaminating" German "racial purity", and asked Hitler to order Forster to stop, Hitler merely told Himmler and Greiser to take up their difficulties with Forster, and not to involve him. Hitler's handling of the Forster–Greiser dispute has often been advanced as an example of Ian Kershaw's theory of "Working Towards the Führer", namely that Hitler issued vague instructions, and allowed his subordinates to work out policy on their own.

After the conquest of Poland, another major dispute broke out between different factions with one centring around Reichsfüherer SS Heinrich Himmler and Arthur Greiser championing and carrying out ethnic cleansing schemes for Poland, and another centring around Hermann Göring and Hans Frank calling for turning Poland into the "granary" of the Reich. At a conference held at Göring's Karinhall estate on 12 February 1940, the dispute was settled in favour of the Göring-Frank view of economic exploitation, and ending mass expulsions as economically disruptive. On 15 May 1940, Himmler showed Hitler a memo entitled "Some Thoughts on the Treatment of Alien Population in the East", which called for expelling the entire Jewish population of Europe into Africa and reducing the remainder of the Polish population to a "leaderless labouring class". Hitler called Himmler's memo "good and correct". Hitler's remark had the effect of scuttling the so-called Karinhall argreement, and led to the Himmler–Greiser viewpoint triumphing as German policy for Poland.

During this period, Hitler built up his forces on Germany's western frontier. In April 1940, German forces invaded Denmark and Norway. In May 1940, Hitler's forces attacked France, conquering Luxembourg, the Netherlands and Belgium in the process. These victories persuaded Benito Mussolini of Italy to join the war on Hitler's side on 10 June 1940. France surrendered on 22 June 1940.

Britain, whose forces evacuated France by sea from Dunkirk, continued to fight alongside other British dominions in the Battle of the Atlantic. After having his overtures for peace rejected by the British, now led by Winston Churchill, Hitler ordered bombing raids on the United Kingdom. The Battle of Britain was Hitler's prelude to a planned invasion. The attacks began by pounding Royal Air Force airbases and radar stations protecting South-East England. However, the Luftwaffe failed to defeat the Royal Air Force. On 27 September 1940, the Tripartite Treaty was signed in Berlin by Saburo Kurusu of Imperial Japan, Hitler, and Ciano. The purpose of the Tripartite Treaty, which was directed against an unnamed power that was clearly meant to be the United States, was to deter the Americans from supporting the British. It was later expanded to include Hungary, Romania and Bulgaria. They were collectively known as the Axis Powers. By the end of October 1940, air superiority for the invasion Operation Sealion could not be assured, and Hitler ordered the bombing of British cities, including London, Plymouth, and Coventry, mostly at night.

In the Spring of 1941, Hitler was distracted from his plans for the East by various activities in North Africa, the Balkans, and the Middle East. In February, German forces arrived in Libya to bolster the Italian forces there. In April, he launched the invasion of Yugoslavia which was followed quickly by the invasion of Greece. In May, German forces were sent to support Iraqi rebel forces fighting against the British and to invade Crete. On 23 May, Hitler released Fuhrer Directive No. 30.

On 22 June 1941, three million German troops attacked the Soviet Union, breaking the non-aggression pact Hitler had concluded with Stalin two years earlier. This invasion seized huge amounts of territory, including the Baltic states, Belarus, and Ukraine. It also encircled and destroyed many Soviet forces, which Stalin had ordered not to retreat. However, the Germans were stopped barely short of Moscow in December 1941 by the Russian winter and fierce Soviet resistance. The invasion failed to achieve the quick triumph Hitler wanted.

A major historical dispute concerns Hitler's reasons for Operation Barbarossa. Some historians such as Andreas Hillgruber have argued that Barbarossa was merely one "stage" of Hitler's Stufenplan (stage by stage plan) for world conquest, which Hillgruber believed that Hitler had formulated in the 1920s. Other historians such as John Lukacs have contended that Hitler never had a stufenplan, and that the invasion of the Soviet Union was an ad hoc move on the part of Hitler due to Britain's refusal to surrender. Lukacs has argued that the reason Hitler gave in private for Barbarossa, namely that Winston Churchill held out the hope that the Soviet Union might enter the war on the Allied side, and that the only way of forcing a British surrender was to eliminate that hope, was indeed Hitler's real reason for Barbarossa. In Lukacs's perspective, Barbarossa was thus primarily an anti-British move on the part of Hitler intended to force Britain to sue for peace by destroying her only hope of victory rather than an anti-Soviet move. Klaus Hildebrand has maintained that Stalin and Hitler were independently planning to attack each other in 1941. Hildebrand has claimed that the news in the spring of 1941 of Soviet troop concentrations on the border led to Hitler engaging in a flucht nach vorn ("flight forward" – i.e. responding to a danger by charging on rather than retreating.) A third fraction comprising a diverse group such as Viktor Suvorov, Ernst Topitsch, Joachim Hoffmann, Ernst Nolte, and David Irving have argued that the official reason given by the Germans for Barbarossa in 1941 was the real reason, namely that Barbarossa was a "preventive war" forced on Hitler to avert an impeding Soviet attack scheduled for July 1941. This theory has been widely attacked as erroneous; the American historian Gerhard Weinberg once compared the advocates of the preventive war theory to believers in "fairy tales".

The Nazi invasion of the Soviet Union reached its apex on 2 December 1941 as part of the 258th Infantry Division advanced to within 15 miles (24 km) of Moscow, close enough to see the spires of the Kremlin. But they were not prepared for the harsh conditions brought on by the first blizzards of winter and in the days that followed, Soviet forces drove them back over 320 kilometres (200 miles).

On 7 December 1941, Japan attacked Pearl Harbor, Hawaii, and four days later, Hitler's formal declaration of war against the United States officially engaged him in war against a coalition that included the world's largest empire (the British Empire), the world's greatest industrial and financial power (the United States), and the world's largest army (the Soviet Union).

On 18 December 1941, the appointment book of the Reichsführer SS Heinrich Himmler shows he met with Hitler, and in response to Himmler's question "What to do with the Jews of Russia?", Hitler's response was recorded as "als Partisanen auszurotten" ("exterminate them as partisans"). The Israeli historian Yehuda Bauer has commented that the remark is probably as close as historians will ever get to a definitive order from Hitler for the genocide carried out during the Holocaust.

In late 1942, German forces were defeated in the second battle of El Alamein, thwarting Hitler's plans to seize the Suez Canal and the Middle East. In February 1943, the Battle of Stalingrad ended with the destruction of the German 6th Army. Thereafter came the Battle of Kursk. Hitler's military judgment became increasingly erratic, and Germany's military and economic position deteriorated along with Hitler's health, as indicated by his left hand's severe trembling. Hitler's biographer Ian Kershaw and others believe that he may have suffered from Parkinson's disease. Syphilis has also been suspected as a cause of at least some of his symptoms, although the evidence is slight.

Following the allied invasion of Sicily (Operation Husky) in 1943, Mussolini was deposed by Pietro Badoglio, who surrendered to the Allies. Throughout 1943 and 1944, the Soviet Union steadily forced Hitler's armies into retreat along the Eastern Front. On 6 June 1944, the Western Allied armies landed in northern France in what was one of the largest amphibious operations in history, Operation Overlord.

Realists in the German army knew defeat was inevitable, and some plotted to remove Hitler from power. In July 1944, as part of Operation Valkyrie in what became known as the 20 July plot, Claus von Stauffenberg planted a bomb in Hitler's headquarters, the Wolfsschanze (Wolf's Lair) at Rastenburg, but Hitler narrowly escaped death. He ordered savage reprisals, resulting in the executions of more than 4,900 people, sometimes by starvation in solitary confinement followed by slow strangulation. The main resistance movement was destroyed, although smaller isolated groups continued to operate.

By late 1944, the Red Army had driven the Germans back into Central Europe and the Western Allies were advancing into Germany. Hitler realized that Germany had lost the war, but allowed no retreats. He hoped to negotiate a separate peace with America and Britain, a hope buoyed by the death of Franklin D. Roosevelt on 12 April 1945. Hitler's stubbornness and defiance of military realities allowed the Holocaust to continue. He ordered the complete destruction of all German industrial infrastructure before it could fall into Allied hands, saying that Germany's failure to win the war forfeited its right to survive. Rather, Hitler decided that the entire nation should go down with him. Execution of this scorched earth plan was entrusted to arms minister Albert Speer, who disobeyed the order.

In April 1945, Soviet forces attacked the outskirts of Berlin. Hitler's followers urged him to flee to the mountains of Bavaria to make a last stand in the National Redoubt. But Hitler was determined to either live or die in the capital. On 20 April, Hitler celebrated his 56th birthday in the Führerbunker ("Führer's shelter") below the Reichskanzlei (Reich Chancellery). Elsewhere, the garrison commander of the besieged Festung Breslau ("fortress Breslau"), General Hermann Niehoff, had chocolates distributed to his troops in honour of Hitler's birthday.

By 21 April, Georgi Zhukov's 1st Belorussian Front had broken through the defences of German General Gotthard Heinrici's Army Group Vistula during the Battle of the Seelow Heights. The Soviets were now advancing towards Hitler's bunker with little to stop them. Ignoring the facts, Hitler saw salvation in the ragtag units commanded by Waffen SS General Felix Steiner. Steiner's command became known as Armeeabteilung Steiner ("Army Detachment Steiner"). But "Army Detachment Steiner" existed primarily on paper. It was something more than a corps but less than an army. Hitler ordered Steiner to attack the northern flank of the huge salient created by the breakthrough of Zhukov's 1st Belorussian Front. Meanwhile, the German Ninth Army, which had been pushed south of the salient, was ordered to attack north in a pincer attack. Late on 21 April, Heinrici called Hans Krebs, chief of the Oberkommando des Heeres (Supreme Command of the Army or OKH), and told him that Hitler's plan could not be implemented. Heinrici asked to speak to Hitler but was told by Krebs that Hitler was too busy to take his call. On 22 April, during one of his last military conferences, Hitler interrupted the report to ask what had happened to Steiner's offensive. There was a long silence. Then Hitler was told that the attack had never been launched, and that the withdrawal from Berlin of several units for Steiner's army, on Hitler's orders, had so weakened the front that the Russians had broken through into Berlin. Hitler asked everyone except Wilhelm Keitel, Hans Krebs, Alfred Jodl, Wilhelm Burgdorf, and Martin Bormann to leave the room, and launched a tirade against the perceived treachery and incompetence of his commanders. This culminated in an oath to stay in Berlin, head up the defence of the city, and shoot himself at the end.

Before the day ended, Hitler again found salvation in a new plan that included General Walther Wenck's Twelfth Army. This new plan had Wenck turn his army – currently facing the Americans to the west – and attack towards the east to relieve Berlin. Twelfth Army was to link up with Ninth Army and break through to the city. Wenck did attack and, in the confusion, made temporary contact with the Potsdam garrison. But the link with the Ninth Army, like the plan in general, was ultimately unsuccessful. On 23 April, Joseph Goebbels made the following proclamation to the people of Berlin:

I call on you to fight for your city. Fight with everything you have got, for the sake of your wives and your children, your mothers and your parents. Your arms are defending everything we have ever held dear, and all the generations that will come after us. Be proud and courageous! Be inventive and cunning! Your Gauleiter is amongst you. He and his colleagues will remain in your midst. His wife and children are here as well. He, who once captured the city with 200 men, will now use every means to galvanize the defence of the capital. The Battle for Berlin must become the signal for the whole nation to rise up in battle ...

The same day, Göring sent a telegram from Berchtesgaden in Bavaria. Göring argued that, since Hitler was cut off in Berlin, he should assume leadership of Germany as Hitler's designated successor. Göring mentioned a time limit after which he would consider Hitler incapacitated. Hitler responded, in anger, by having Göring arrested. Later when Hitler wrote his will on 29 April, Göring was removed from all his positions in the government. Further on the 23 April, Hitler appointed General der Artillerie Helmuth Weidling as the commander of the Berlin Defense Area. Weidling replaced Lieutenant General (Generalleutnant) Helmuth Reymann and Colonel (Oberst) Ernst Kaether. Hitler also appointed Waffen SS General (SS Brigadeführer) Wilhelm Mohnke the (Kommandant) Battle Commander for the defence of the government sector (Zitadelle sector) that included the Reich Chancellery and Führerbunker.

By the end of the day on 27 April, Berlin was completely cut off from the rest of Germany. On 28 April, Hitler discovered that SS leader Heinrich Himmler was trying to discuss surrender terms with the Western Allies (through the Swedish diplomat Count Folke Bernadotte). Hitler ordered Himmler's arrest and had Hermann Fegelein (Himmler's representative for the SS at Hitler's HQ in Berlin) shot.

During the night of 28 April, Wenck reported that his Twelfth Army had been forced back along the entire front. He noted that no further attacks towards Berlin were possible. General Alfred Jodl (Supreme Army Command) did not provide this information to Hans Krebs in Berlin until early in the morning of 30 April. On 29 April, Hitler dictated his will and political statement to his private secretary,Traudl Junge. Hans Krebs, Wilhelm Burgdorf, Joseph Goebbels, and Martin Bormann witnessed and signed this last will and testament of Adolf Hitler. On the same day, Hitler was informed of the assassination of Italian dictator Benito Mussolinion 28 April, which is presumed to have increased his determination to avoid capture. On 30 April 1945, after intense street-to-street combat, when Soviet troops were within a block or two of the Reich Chancellery, Hitler committed suicide, shooting himself in the temple with a Walther PPK while simultaneously biting into a cyanide capsule. Hitler had at various times in the past contemplated suicide, and the Walther was the same pistol that his niece, Geli Raubal had used in her suicide. Hitler's body and that of Eva Braun were put in a bomb crater, doused in gasoline by SS Sturmbannführer Otto Günsche and other Führerbunker aides, and cremated as the Red Army advanced and shelling continued.

On 2 May, Berlin surrendered. In the postwar years there were conflicting reports about what happened to Hitler's remains. After the fall of the Soviet Union, records found in the Soviet archives revealed that the remains of Hitler, Eva Braun, Joseph and Magda Goebbels, the six Goebbels children, General Hans Krebs and Hitler's dogs, were collected, moved and secretly buried in graves near Rathenow in Brandenburg. In 1970, the remains were disinterred, cremated and scattered in the Elbe River by the Soviets. According to the Russian Federal Security Service, a fragment of human skull stored in its archives and displayed to the public in a 2000 exhibition came from the remains of Hitler's body. The authenticity of the skull has been challenged by historians and researchers. In fact, DNA analysis conducted in 2009 showed the skull fragment to be that of a woman, and analysis of the sutures between the skull plates indicated an age between 20 and 40 years old at the time of death.