He was born to Otto Jan Józefat von Zelewski, a Roman Catholic, and his Lutheran wife Elżbieta Ewelina Szymańska (written in German - Schimansky). Born Erich Julius Eberhard von Zelewski, he legally added "von dem Bach" to the family name late in the 1933. He went on to have "Zelewski" officially removed from his name in November 1941 because of its Polish sound.

His great-great-great-grandfather was Michał Żelewski (c. 1700 - 1785), who was a Polish nobleman; he owned the villages of Milwino, Niepoczołowice and Zakrzewo in Pomerania. Żelewski's marriage to Anna Zofia von Pirch produced a son, Franciszek von Zelewski (c. 1735 - 1788). The younger von Zelewski married Ewa von Kętrzyńska, who in 1778 gave birth to Andrzej Klemens von Zelewski. Andrzej married Konkordia Wilhelmina Henrietta von Grubba. Their eldest son, Otton August Ludwik Rudolf von Zalewski (born 1820 in Zakrzewo, died June 28, 1878 in Zęblewo), was von dem Bach's grandfather. Roman Catholic Church sources claim that in 1855 in Strzepcz Otton August von Zelewski married Antonia Fryderyka von Żelewska (apparently from another Zelewski family). One of their sons was Otton Jan von Zelewski (born May 19, 1859 in Zęblewo; died April 12, 1911 in Dortmund), who married Elżbieta Ewelina Szymańska about 1890. They had three daughters and three sons, one of whom was Erich Julius Eberhard von Zelewski.

He was born in Lauenburg, Pomerania, German Empire (now Lębork, Poland), on March 1, 1899, the son of a Junker. Despite his aristocratic genealogy, he seemed to have grown up in poverty; his father proved unable to establish a career and undertook a range of jobs, including agriculture. At the time of his death on April 17, 1911 in Dortmund he was employed as an insurance clerk. Otto's lack of success owed partially to his being the brother of Emil von Zalewski, who on August 17, 1891, while leading a colonial force armed with guns against Wehe insurgents in German East Africa (later named Tanganyika, now part of Tanzania), was speared to death as his force was annihilated in the battle of Rugarto. Being militarily outwitted by African blacks armed with spears against a well armed force was considered shameful, and the family was disgraced. Following his father's death, von dem Bach's uncle Oskar von Zalewski, a soldier, developed a very close relationship with the boy and encouraged him to also pursue a military career. In November 1914, Erich von Zalewski volunteered for the Prussian army, becoming one of the youngest recruits and serving until the end of World War I. He was wounded twice and won the Iron Cross.

After the war, he remained in the Reichswehr and, among other duties, fought in the Silesian Uprisings, where he earned a reputation and received several decorations. In 1924, von Zalewski transferred to the Grenzschutz (border guards). On October 23, 1925, he legally changed his surname to `von dem Bach - Zalewski`.

He left the Grenzschutz in 1930, when he joined the Nazi Party, becoming a member of the SS in 1931. He was rapidly promoted and, by the end of 1933, had reached the rank of SS - Brigadeführer (Major General). However, he quarrelled with his staff officer Anton von Hohberg und Buchwald. In 1934 he received the Cross of Honor (German: Ehrenkreuz).

A source of considerable annoyance for him was that three of his sisters married Jewish men, and in 1946, claimed under interrogation that this ruined his reputation in the army forcing him to leave the Reichswehr.

A Nazi party member of the Reichstag from 1932 to 1944, he participated in the Night of the Long Knives in 1934, taking the opportunity to have Anton von Hohberg und Buchwald murdered. He served in various Nazi Party posts, initially in East Prussia and after 1936 in Silesia. By 1937, he had become the Höherer SS - und Polizeiführer (HSSPF - Higher SS and Police Leader) in Silesia.
After the war broke out, units under his command took part in reprisal actions and the shooting of POWs during the September Campaign, although von dem Bach was not personally present. On 7 November 1939, SS chief Heinrich Himmler offered him the post of Commissioner for the Strengthening of Germandom in Silesia. His duties included mass resettlements and the confiscation of private property. By August 1940, his units had forced more than 20,000 Żywiec families to leave their homes.

On 22 June 1941, von dem Bach - Zelewski became the Higher SS and Police Leader in the region of Silesia. He would provide the initial impetus of building a concentration camp at the Polish artillery barracks in the Zasole suburb of Oświęcim (Auschwitz); a location scouted by his Obergruppfuhrer Arpad Wigand. In July 1943, he became commander of the so-called "Bandenkämpfverbände" ("Band - fighting Units"), responsible for the mass murder of 35,000 civilians in Riga and more than 200,000 in Belarus and eastern Poland. The authorities designated him as the future HSSPF in Moscow; however, the Wehrmacht failed to take the city. Until 1943, von dem Bach - Zalewski remained the HSSPF in command of "anti - partisan" units on the central front, a special command created by Adolf Hitler. Von dem Bach - Zalewski was the only HSSPF in the occupied Soviet territories to retain genuine authority over the police after Hans - Adolf Prützmann and Jockeln lost theirs to the civil administration.

In February 1942, he was hospitalized, later claiming that this was due to a nervous breakdown connected with the ethnic cleansing in Belarus, especially the genocide of the Jews. Wireless intercepts decoded by British intelligence suggest, however, that his illness was strictly physical. He resumed his post in July, with no apparent reduction in his ruthlessness.

In June 1942, after the assassination of Reinhard Heydrich in Prague, Hitler wanted von dem Bach - Zelewski to take Heydrich's place as Reich Protector of Bohemia and Moravia. When Himmler argued that von dem Bach - Zelewski could not be spared due to the prevailing military situation, Hitler relented and appointed Kurt Daluege to the position.

On 12 July 1943, von dem Bach - Zalewski received command of all anti - partisan actions in Belgium, Belarus, France, the General Government, the Netherlands, Norway, Ukraine, Yugoslavia, and parts of the Bezirk Bialystok. In practice, his activities remained confined to Belarus and contiguous parts of Russia.

Von dem Bach-Zelewski's tactics produced high civilian deaths and relatively minor military gains. German forces would more or less encircle partisan controlled areas before closing in. Since deploying the necessary forces was time consuming and conspicuous, the partisans would be forewarned and many would slip away, after hiding their heavier equipment and much of their supplies, while the remaining partisans would carry out a fighting withdrawal, picking off the lead German troops, often killing more men than they lost.

In fighting these irregular battles, the Germans wantonly slaughtered civilians in order to inflate the figures of "enemy losses"; indeed, far more fatalities were recorded than weapons captured. After an operation was completed, no permanent military presence would be maintained, allowing the partisans to slip back in, retrieve their hidden stocks and pick up where they had left off (occasionally, partisans would not return but would begin operating from the positions to which they had retreated). Even when successful, von dem Bach - Zalewski accomplished little more than forcing partisans to relocate, and swelling their numbers with enraged civilians.

In 1944, he took part in front line fighting in the Kovel area, but in March he had to go to Germany for medical treatment. Himmler assumed all his posts.

On 2 August 1944, he took command of all troops fighting against the Warsaw Uprising as Korpsgruppe Bach. Units under his command killed approximately 200,000 civilians (more than 65,000 in mass executions) and an unknown number of POWs. After more than two months of heavy fighting and the total destruction of Warsaw he finally managed to control the city. For his actions in Warsaw von dem Bach - Zalewski was awarded on September 30, 1944, the Knight's Cross of the Iron Cross by the Nazi regime. Despite the slaughter and destruction wrought on Warsaw, he is alleged to have personally saved Chopin's heart from destruction. The heart is preserved in within a Warsaw church.

Between 26 January and 10 February 1945, von dem Bach - Zalewski commanded X SS Armeekorps, one of the "paper - corps", in Germany, but his unit was annihilated after less than two weeks.

Von dem Bach - Zelewski went into hiding and tried to leave the country. However, US military police arrested him on 1 August 1945. In exchange for his testimony against his former superiors at the Nuremberg Trials, von dem Bach - Zelewski never faced trial for any war crimes. Similarly, he never faced extradition to Poland or to the USSR. He left prison in 1949.

In 1951, von dem Bach - Zalewski claimed that he had helped Hermann Göring commit suicide in 1946. As evidence, he produced cyanide capsules to the authorities with serial numbers not far removed from the one used by Göring. The authorities never verified von dem Bach - Zalewski's claim, however, and did not charge him with aiding Göring's death. Most modern day historians dismiss von dem Bach - Zalewski's claim and agree that a U.S. Army contact within the Palace of Justice's prison at Nuremberg most likely aided Göring in his suicide.

Also in 1951, von dem Bach - Zelewski was sentenced to 10 years in a labor camp for the murder of political opponents in the early 1930s; however, he did not serve time until 1958, when he was convicted of killing Anton von Hohberg und Buchwald, an SS officer, during the Night of the Long Knives, and was sentenced to four and a half years imprisonment. In 1961, he was sentenced to an additional 10 years in home custody for the murder of 10 German Communists in the early 1930s. None of the sentences referred to his role in Poland, in the East and his participation in the Holocaust, although he openly admitted to having murdered Jews. He died in a Munich prison on 8 March 1972.