Field Marshal Arthur Wellesley, 1st Duke of Wellington, KG, KP, GCB, GCH, PC, FRS (c. 29 April / 1 May 1769 – 14 September 1852), was an Anglo - Irish soldier and statesman, and one of the leading military and political figures of the 19th century. He is often referred to as simply "The Duke of Wellington", even after his death, when there have been subsequent Dukes of Wellington.

Born in Ireland to a prominent family of Hiberno - Norman origins and Old English culture, he was commissioned an ensign in the British Army in 1787. Serving in Ireland as aide - de - camp to two successive Lords Lieutenant of Ireland he was also elected as a Member of Parliament in the Irish House of Commons. A colonel by 1796, Wellesley saw action in the Netherlands and later India where he fought in the Fourth Anglo - Mysore War at the Battle of Seringapatam. He was later appointed governor of Seringapatam and Mysore. Wellesley rose to prominence as a general during the Peninsular campaign of the Napoleonic Wars, and was promoted to the rank of field marshal after leading the allied forces to victory against the French at the Battle of Vitoria in 1813. Following Napoleon's exile in 1814, he served as the ambassador to France and was granted a Dukedom. During the Hundred Days in 1815, he commanded the allied army which, with a Prussian army under Blücher, defeated Napoleon at the Battle of Waterloo. Wellesley's battle record is exemplary, ultimately participating in some 60 battles throughout his military career. He was twice Prime Minister under the Tory party and oversaw the passage of the Catholic Relief Act 1829. He was Prime Minister from 1828 – 30 and served briefly in 1834. He was unable to prevent the passage of the Reform Act of 1832 and continued as one of the leading figures in the House of Lords until his retirement. He remained Commander - in - Chief of the British Army until his death in 1852.

The earliest mention of the Wellesley family is in 1180. It places Wellington’s ancestry among the conquering elite of the Norman conquest of England of 1066; the family had been granted lands to the south of Wells, Somerset, around a settlement still known as Wellesley Farm. "Wesley" was inherited from the childless wealthy husband of an aunt when, in 1728, Wellington's patrilineal grandfather Garret Colley, a landlord who lived at Rahin near Carbury, County Kildare, changed his surname to Wesley. The Colleys had lived in that part of Kildare since the Norman Invasion of Ireland in 1169 – 72. In 1917 the Kildare historian Lord Walter FitzGerald, writing about the ruins of Carbury Castle, mentioned that "Elizabethan Castle which since 1588 has been in the possession of the family of Cowley or Colley, from whom the Dukes of Wellington are descended in the direct male line".

Wellington was born "The Honourable Arthur Wesley", the fourth son - third of five surviving sons - to Garret Wesley, 1st Earl of Mornington, and Anne, the eldest daughter of Arthur Hill, Viscount Dungannon. He was most likely born at their townhouse, 24 Upper Merrion Street, Dublin, now the upmarket "Merrion Hotel". His biographers mostly follow the contemporary newspaper evidence in saying he was born 1 May 1769, the day he was baptised. Other places have been put forward as the location of his birth: Mornington House, Dublin — as his father claimed; the house next door which is no longer there; the Dublin packet boat; and the family estate of Athy, as the Duke apparently put on his 1851 census return, which is now burnt.

He spent most of his childhood at his family's two homes, the first a large house in Dublin and the second, Dangan Castle, 3.1 miles (5 km) north of Summerhill on the Trim road in County Meath, part of the Province of Leinster. In 1781 Arthur's father died and his eldest brother Richard inherited his father's earldom. Two of his other brothers were later raised to the peerage as Baron Maryborough and Baron Cowley.

He went to the diocesan school in Trim when at Dangan, Mr. Whyte's Academy when in Dublin, and at Brown's School in Chelsea when in London. He then enrolled at Eton, where he studied from 1781 to 1784. His loneliness there caused him to hate it, and makes it highly unlikely that he actually said, "The Battle of Waterloo was won on the playing fields of Eton". Moreover, Eton had no playing fields at the time. A lack of success at Eton, combined with a shortage of family funds from his father's death, led to a move to Brussels in Belgium with his mother in 1785. Until his early twenties, Arthur continued to show little sign of distinction and his mother grew increasingly concerned at his idleness, stating, "I don't know what I shall do with my awkward son Arthur".

A year later, Arthur enrolled in the French Royal Academy of Equitation in Angers, where he progressed significantly, becoming a good horseman and learning French, which was later to prove very useful. Upon returning to England in late 1786, he astonished his mother with his improvement.

Despite his new promise he had yet to find a job and his family was still short of money, so upon the advice of his mother, his brother Richard asked his friend the Duke of Rutland (then Lord Lieutenant of Ireland) to consider Arthur for a commission in the army. Soon after, on 7 March 1787 he was gazetted ensign in the 73rd Regiment of Foot. In October, with the assistance of his brother, he was assigned as aide - de - camp, on ten shillings a day (twice his pay as an ensign), to the new Lord Lieutenant of Ireland Lord Buckingham. He was also transferred to the new 76th Regiment forming in Ireland and on Christmas Day, 1787, was promoted to Lieutenant. During his time in Dublin his duties were mainly social; attending balls, entertaining guests and providing advice to Buckingham. While in Ireland, he over extended himself in borrowing due to his occasional gambling, but in his defence stated that "I have often known what it was to be in want of money, but I have never got helplessly into debt".

Two years later, in June 1789, he transferred to the 12th Light Dragoons, still as a lieutenant and according to his biographer Richard Holmes he also dipped a reluctant toe into politics. Shortly before the general election of 1789, he went to the "rotten borough" of Trim to speak against the granting of the title "Freeman" of Dublin to the parliamentary leader of the Irish Patriot Party, Henry Grattan. Succeeding, he was later nominated and duly elected as a Member of Parliament for Trim in the Irish House of Commons. Because of the limited suffrage at the time, he sat in a parliament where at least two - thirds of the members owed their election to the landowners of fewer than a hundred boroughs. Wellesley continued to serve at Dublin Castle, voting with the government in the Irish parliament over the next two years and in 1791 he became a Captain and was transferred to the 18th Light Dragoons.

It was during this period that he grew increasingly attracted to Kitty Pakenham, the daughter of Edward Pakenham, 2nd Baron Longford. She was described as being full of 'gaiety and charm'. In 1793 he sought her hand, but was turned down by her brother Thomas, Earl of Longford, who considered Wellesley to be a young man, in debt, with very poor prospects. An aspiring amateur musician, Wellesley, devastated by the rejection, burnt his violins in anger, and resolved to pursue a military career in earnest. Gaining further promotion (largely by purchasing his rank, which was common in the British Army at the time), he became a Major in the 33rd Regiment in 1793. A few months later, in September, his brother lent him more money and with it he purchased a Lieutenant - Colonelcy in the 33rd.

In 1793, the Duke of York was sent to Flanders in command of the British contingent of an allied force destined for the invasion of France. In 1794, the 33rd regiment was sent to join the force and Wellesley set sail from Cork for Flanders in June, destined for his first real battle experience. During the campaign he rose to command a brigade and in September Wellesley's unit came under fire just east of Breda, just before the Battle of Boxtel. For the latter part of the campaign, during the winter, his unit defended the line of the Waal River, during which time he became ill for a while, owing to the damp environment. Though the campaign was to prove unsuccessful, with the Duke of York's force returning in 1795, Wellesley was to learn several valuable lessons, including the use of steady fire lines against advancing columns and of the merits of supporting sea - power. He concluded that many of the campaign's blunders were due to the faults of the leaders and the poor organisation at Headquarters. He remarked later of his time in the Netherlands that "At least I learned what not to do, and that is always a valuable lesson".

Returning to England in March 1795, he was returned as a Member of Parliament for Trim for a second time. He hoped to be given the position of secretary of war in the new Irish government but the new lord - lieutenant, Lord Camden, was only able to offer him the post of Surveyor - General of the Ordnance. Declining the post, he returned to his regiment, now at Southampton preparing to set sail for the West Indies. After seven weeks at sea, a storm forced the fleet back to Poole, England. The 33rd was given time to convalesce and a few months later, Whitehall decided to send the regiment to India. Wellesley was promoted full colonel by seniority a few weeks later and in 1796 set sail for Calcutta with his regiment.

Arriving in Calcutta in February 1797 he spent several months there, before being sent on a brief expedition to the Philippines, where he established a list of new hygiene precautions for his men to deal with the unfamiliar climate. Returning in November to India, he learnt that his elder brother Richard, now known as Lord Mornington, had been appointed as the new Governor - General of India. As part of the campaign to extend the rule of the British East India Company, the Fourth Anglo - Mysore War broke out in 1798 against the Sultan of Mysore, Tippoo Sultan. Arthur's brother Richard ordered that an armed force be sent to capture Seringapatam and defeat Tippoo. Under the command of General Harris, some 24,000 troops were dispatched to Madras (to join an equal force being sent from Bombay in the west). Arthur and the 33rd sailed to join them in August.

In 1798 he changed the spelling of his surname to "Wellesley", up to this time he was still known as Wesley, which his oldest brother considered the ancient and proper spelling.

After extensive and careful logistic preparation (that would become one of Wellesley's main attributes) the 33rd left with the main force in December and travelled across 250 miles (400 km) of jungle from Madras to Mysore. On account of his brother, during the journey, Wellesley was given an additional command, that of chief advisor to the Nizam of Hyderabad's army (sent to accompany the British force). This position was to cause friction amongst many of the senior officers (some of whom were senior to Wellesley). Much of this friction was put to rest after the Battle of Mallavelly, some 20 miles (32 km) from Seringapatam, in which Harris's army attacked a large part of the sultan's army. During the battle, Wellesley led his men, in a line of battle of two ranks, against the enemy to a gentle ridge and gave the order to fire. After an extensive repetition of volleys, followed by a bayonet charge, the 33rd, in conjunction with the rest of Harris's force, forced Tippoo's infantry to retreat.

Immediately after their arrival at Seringapatam on 5 April, the Battle of Srirangapatna began and Wellesley was ordered to lead a night attack on the village of Sultanpettah, adjacent to the fortress to clear the way for the artillery. Because of the enemy's strong defensive preparations, and the darkness, with the resulting confusion, the attack failed with 25 casualties. Wellesley suffered a minor injury to his knee from a spent musket - ball. Although they would reattack successfully the next day, after time to scout ahead the enemy's positions, the affair had an impact on Wellesley. He resolved "never to attack an enemy who is preparing and strongly posted, and whose posts have not been reconnoitred by daylight".

A few weeks later, after extensive artillery bombardment, a breach was opened in the main walls of the fortress of Seringapatam. An attack led by Major - General Baird secured the fortress. Wellesley secured the rear of the advance, posting guards at the breach and then stationed his regiment at the main palace. After hearing news of the death of the Tippoo Sultan, Wellesley was the first at the scene to confirm his death, checking his pulse. Over the coming day, Wellesley grew increasingly concerned over the lack of discipline amongst his men, who drank and pillaged the fortress and city. To restore order, several soldiers were flogged and four hanged.

After battle and the resulting end of the war, the main force under General Harris left Seringapatam and Wellesley, aged 30, stayed behind to command the area as the new Governor of Seringapatam and Mysore. He took residence within the Sultan's summer palace and reformed the tax and justice systems in his province to maintain order and prevent bribery. He also hunted down the mercenary 'King' Dhoondiah Waugh, who had escaped from prison in Seringapatam during the battle. Wellesley, with command of four regiments, defeated Dhoondiah's larger rebel force, along with Dhoondiah himself who was killed in the battle. He paid for the future upkeep of Dhoondia's orphaned son.

Whilst in India, Wellesley was ill for a considerable time, first with severe diarrhea from the water and then with fever, followed by a serious skin infection caused by trichophyton. He received good news when in September 1802 he learnt that he had been promoted to the rank of Major - General. Wellesley had been gazetted Major - General on 29 April, but the news took several months to reach him by sea. He remained at Mysore until November when he was sent to command an army in the Second Anglo - Maratha War.

Wellesley decided that he must act boldly to defeat the numerically larger force of the Maratha Empire (as he concluded a long defensive war would ruin his army). With the logistic assembly of his army complete (24,000 men in total) he gave the order to break camp and attack the nearest Maratha fort on 8 August 1803. The fort surrendered on 12 August after an infantry attack had exploited an artillery - made breach in the wall. With the fort now in British control Wellesley was able to extend control southwards to the river Godavari.

Despite the damage done to the Maratha army, the battle did not end the war. A few months later in November, Wellesley attacked a larger force near Argaum, leading his army to victory again, with an astonishing 5,000 enemy dead at the cost of only 361 British casualties. A further successful attack at the fortress at Gawilghur, combined with the victory of General Lake at Delhi forced the Maratha to a peace settlement (not concluded until a year later). His biographer Richard Holmes remarked that his experiences in India had an important influence on his personality and military tactics, teaching him much about military matters that would prove vital to his success in the Peninsular War. These included a strong sense of discipline through drill and order, the use of diplomacy to gain allies, and the vital necessity for a secure supply line. He also established a high regard for the acquisition of intelligence through scouts and spies. His personal tastes also developed, including dressing himself in white trousers, a dark tunic, with Hessian boots and black cocked hat (that later became synonymous as his style).

Wellesley had grown tired of his time in India, remarking "I have served as long in India as any man ought who can serve anywhere else". In June 1804 he applied for permission to return home and, as a reward for his service in India, in September he was made a Knight of the Bath. Whilst in India, Wellesley had amassed a fortune of £42,000 (considerable at the time), consisting mainly of prize money from his campaign. When his brother's term as Governor - General of India ended in March 1805, the brothers returned together to England on HMS Howe. Arthur, coincidentally, stopped on his voyage at the little island of Saint Helena and stayed in the same building to which Napoleon I of France would later be exiled.

After returning home, the Wellesleys were forced to defend their extravagant and unauthorized deployment of British forces in India. Wellesley then served in the abortive Anglo - Russian expedition to north Germany in 1805, taking a brigade to Elbe. Wellesley upon his return received good news, when, owing to his new title and status, he was given permission to marry Kitty Pakenham (from her family). He married her in Dublin on 10 April 1806. The marriage would later prove to be unsatisfactory and the two would spend years apart while Wellesley was campaigning. He then took a period of extended leave from the army and was elected Tory member of Parliament for Rye in January 1806. A year later, he was elected MP for Newport on the Isle of Wight and was then appointed to serve as Chief Secretary for Ireland, under the Duke of Richmond (at the same he was made a privy counsellor).

Wellesley was in Ireland, when in May 1807 he heard of the British expedition to Denmark. He decided to go, stepping down from his political appointments and was appointed to command an infantry brigade in the Second Battle of Copenhagen which took place in August. He fought at the Køge, during which the men under his command took 1,500 prisoners, with Wellesley later present during the surrender. By 30 September he had returned to England and was raised to the rank of lieutenant general. In June 1808 he accepted the command of an expedition of 9,000 men. Preparing to sail for an attack on the Spanish colonies in South America (to assist the Latin American patriot Francisco de Miranda) his force was instead ordered to sail for Portugal, to take part in the Peninsular Campaign and rendezvous with 5,000 troops from Gibraltar.

Ready for battle, he left Cork on 12 July 1808 to participate in the war against French forces in Iberia, with his skills as a commander tested and developed. According to the historian Robin Neillands, "Wellesley had by now acquired the experience on which his later successes were founded. He knew about command from the ground up, about the importance of logistics, about campaigning in a hostile environment. He enjoyed political influence and realised the need to maintain support at home. Above all, he had gained a clear idea of how, by setting attainable objectives and relying on his own force and abilities, a campaign could be fought and won."

Wellesley defeated the French at the Battle of Roliça and the Battle of Vimeiro in 1808 but was superseded in command immediately after the latter battle. General Dalrymple then signed the controversial Convention of Sintra, which stipulated that the British Royal Navy transport the French army out of Lisbon with all their loot, and insisted on the association of the only available government minister, Wellesley. Dalrymple and Wellesley were recalled to Britain to face a Court of Enquiry. Wellesley had agreed to sign the preliminary armistice, but had not signed the convention, and was cleared.

Meanwhile, Napoleon himself entered Spain with his veteran troops to put down the revolt; the new commander of the British forces in the Peninsula, Sir John Moore, died during the Battle of Corunna in January 1809.

Although overall the land war with France was not going well from a British perspective, the Peninsula was the one theatre where they, with the Portuguese, had provided strong resistance against France and her allies. This contrasted with the disastrous Walcheren expedition, which was typical of the mismanaged British operations of the time. Wellesley submitted a memorandum to Lord Castlereagh on the defence of Portugal. He stressed its mountainous frontiers and advocated Lisbon as the main base because the Royal Navy could help to defend it. Castlereagh and the cabinet approved the memo, appointed him head of all British forces in Portugal, and raised their number from 10,000 to 26,000 men.

Wellesley arrived in Lisbon on 22 April 1809 onboard HMS Surveillante, after narrowly escaping shipwreck. Reinforced, he took to the offensive. In the Second Battle of Porto he crossed the Douro river in a daylight coup de main, and routed Marshal Soult's French troops in Porto.

With Portugal secured, Wellesley advanced into Spain to unite with General Cuesta's forces. The combined allied force prepared for an assault on Victor's I Corps at Talavera, July 23. Cuesta, however, was reluctant to agree, and was only persuaded to advance on the following day. The delay allowed the French to withdraw, but Cuesta sent his army headlong after Victor, and found himself faced by almost the entire French army in New Castile — Victor had been reinforced by the Toledo and Madrid garrisons. The Spanish retreated precipitously, necessitating two British divisions advancing to cover their retreat.

The next day, July 27, at the Battle of Talavera the French advanced in three columns and were repulsed several times throughout the day by Wellesley, but at a heavy cost to the British force. In the aftermath Marshal Soult's army was discovered to be advancing south, threatening to cut Wellesley off from Portugal. Wellesley moved east on August 3 to block it, leaving 1,500 wounded in the care of the Spanish, intending to confront Soult before finding out that the French were in fact 30,000 strong. The British commander sent the Light Brigade on a dash to hold the bridge over the Tagus River at Almaraz. With communications and supply from Lisbon secured for now, Wellesley considered joining with Cuesta again but found out that his Spanish ally had abandoned the British wounded to the French and was thoroughly uncooperative, promising and then refusing to supply the British forces, aggravating Wellesley and causing considerable friction between the British and their Spanish allies. The lack of supplies, coupled with the threat of French reinforcement (including the possible inclusion of Napoleon himself) in the spring, led to the British deciding to retreat into Portugal.

In 1810, a newly enlarged French army under Marshal André Masséna invaded Portugal. British opinion both at home and in the army was negative and there were suggestions that they must evacuate Portugal. Instead, Wellington first slowed the French down at Buçaco; he then prevented them from taking the Lisbon Peninsula by the construction of his massive earthworks, the Lines of Torres Vedras, which had been assembled in complete secrecy and had flanks guarded by the Royal Navy. The baffled and starving French invasion forces retreated after six months. Wellington's pursuit was frustrated by a series of reverses inflicted by Marshal Ney in a much lauded rear guard campaign. Ney worsted Wellington at Pombal and Redinha, allowing Masséna to evade Wellington and escape from Portugal.

In 1811 Masséna returned toward Portugal to relieve Almeida; Wellington narrowly checked the French at the Battle of Fuentes de Onoro. Simultaneously, his subordinate, Viscount Beresford, fought Soult's 'Army of the South' to a mutual bloody standstill at the Battle of Albuera. In May, Wellington was promoted to full general for his services. The French abandoned Almeida, slipping away from British pursuit, but retained the twin Spanish fortresses of Ciudad Rodrigo and Badajoz, the 'Keys' guarding the roads through the mountain passes into Portugal.

In 1812 Wellington finally captured Ciudad Rodrigo by a rapid movement as the French went into winter quarters, storming it before they could react. He then moved south quickly, besieged the fortress of Badajoz for a month and captured it during one bloody night. On viewing the aftermath of the Storming of Badajoz, Wellington lost his composure and cried at the sight of the bloody carnage in the breaches.

His army now was a veteran British force reinforced in by units of the retrained Portuguese army. Campaigning in Spain, he routed the French at the Battle of Salamanca, taking advantage of a minor French mispositioning. The victory liberated the Spanish capital of Madrid. As reward, he was created "Earl" and then "Marquess of Wellington" and given command of all Allied armies in Spain. Wellington attempted to take the vital fortress of Burgos, which linked Madrid to France. But failure, due in part to a lack of siege guns, forced him into a headlong retreat with the loss of over 2,000 casualties.

The French abandoned Andalusia, and combined the troops of Soult and Marmont outnumbering the British, to put the British forces into a precarious position. Wellington withdrew his army and joined with the smaller corps commanded by Rowland Hill began to retreat to Portugal. Marshal Soult declined to attack. Despite the withdrawal, the victory at Salamanca had forced the French to cede control of southern Spain, and the temporary loss of Madrid damaged the prestige of the Bonapartist regime.

In 1813, Wellington led a new offensive, this time against the French line of communications. He struck through the hills north of Burgos, the Tras os Montes, and switched his supply line from Portugal to Santander on Spain's north coast; this led to the French abandoning Madrid and Burgos. Continuing to outflank the French lines, Wellington caught up with and smashed the army of King Joseph Bonaparte in the Battle of Vitoria, for which he was promoted to field marshal. He personally led a column against the French centre, while other columns were commanded by Sir Thomas Graham and Rowland Hill and looped around the French right and left (this battle became the subject of Beethoven's opus 114, Wellington's Victory). The British troops broke ranks to loot the abandoned French wagons instead of pursuing the beaten foe. This gross abandonment of discipline caused an enraged Wellington to write in a famous dispatch to Earl Bathurst,"We have in the service the scum of the earth as common soldiers".

Although later, when his temper had cooled, he extended his comment to praise the men under his command saying that though many of the men were, "the scum of the earth; it is really wonderful that we should have made them to the fine fellows they are".

After taking the small fortresses of Pamplona, Wellington invested San Sebastián but was frustrated by the obstinate French garrison, losing 693 dead and 316 captured in a failed assault and suspending the siege at the end of July. Soult's relief attempt was blocked by the Spanish Army of Galicia at San Marcial, allowing the Allies to consolidate their position and tighten the ring around the city, which fell in September after a second spirited defence. Wellington then forced Soult's demoralised and battered army into a fighting retreat into France, punctuated by battles at the Pyrenees, Bidassoa and Nivelle. Wellington invaded southern France, winning at the Nive and Orthez. Wellington's final battle against his rival Soult occurred at Toulouse, where the Allied divisions were badly mauled storming the French redoubts, losing some 4,600 men. Despite this momentary victory, news arrived of Napoleon's defeat and abdication and Soult, seeing no reason to continue the fighting agreed on a ceasefire with Wellington, allowing Soult to evacuate the city.

Hailed as the conquering hero by the British, Wellington was created "Duke of Wellington", a title still held by his descendants (as he did not return to England until the Peninsular War was over, he was awarded all his patents of nobility in a unique ceremony lasting a full day). Although Wellesley spent nearly six years driving the French Army from Spain and removing Joseph Bonaparte from the Spanish throne, he has received little recognition in Spain: history, as taught in Spanish schools, minimizes his contribution and those of the British and Portuguese soldiers that fought with him. He received some recognition during his lifetime (the title of "Duque de Ciudad Rodrigo") and the Spanish King Ferdinand VII allowed him to keep part of the works of art from the Royal Collection which he had recovered from the French. His equestrian portrait features prominently in the Monument to the Battle of Vitoria, in present day Vitoria - Gasteiz.

He was appointed ambassador to France, then took Lord Castlereagh's place as first plenipotentiary to the Congress of Vienna, where he strongly advocated allowing France to keep its place in the European balance of power. On 2 January 1815 the title of his Knighthood of the Bath was converted to Knight Grand Cross upon the expansion of that order.

On 26 February 1815, Napoleon escaped from Elba and returned to France. He regained control of the country by May and faced a renewed alliance against him. Wellington left Vienna for what became known as the Waterloo Campaign. He arrived in Belgium to take command of the British - German army and their allied Dutch - Belgians, all stationed alongside the Prussian forces of Gebhard Leberecht von Blücher.

Napoleon's tactics have been criticised as lacking in the brilliance he had exhibited earlier in his career. Given the forces arrayed against him, including the Russians and Austrians mobilising in the east, the choices that confronted him, and his responses to them, were brutally clear: he would use his "central position"; after he had defeated the Prussians at Ligny on 16 June, and compelled Wellington's forces to retreat, Napoleon's aim was to keep the Prussians and the Allies from combining in the same battle, if he was to have any chance of victory and the possibility of a peace with Austria and Russia.

The French invaded Belgium, defeated the Prussians at Ligny, and fought an indecisive battle with Wellington at the Battle of Quatre Bras. These events compelled the Anglo - Allied army to retreat to a ridge on the Brussels road, just south of the small town of Waterloo. On 17 June, a torrential rain soaked in, hampering movement. The next day, on 18 June, the Battle of Waterloo was fought. This was the first time Wellington had encountered Napoleon, and he commanded an Anglo - German - Dutch army that consisted of 68,000 troops, 24,000 of whom were British.

Much historical discussion has been made about Napoleon's decision to send 33,000 troops under Marshal Grouchy to intercept the Prussians, but — having defeated Blücher at Ligny on 16 June and forced the Allies to retreat in divergent directions — Napoleon may have been strategically astute in a judgement that he would have been unable to beat the combined Allied forces on one battlefield. Wellington's comparable strategic gamble was to leave 17,000 troops and artillery at Hal, northwest of the Mont Saint Jean. The potential benefits of this decision were not only to provide Wellington with a reserve with which to fight again the following day, should the action on 18 June prove inconclusive, but to protect his line of retreat to the sea.

Napoleon wished to divide Wellington and Blücher, rather than drive them together. His plan was to pin Wellington's right with an attack on Hougoumont, then shatter Wellington's left position with an all-out infantry assault. This tactic had been successful with other opponents earlier in Napoleon's career.

But Hougoumont held out, defended by the Coldstream Guards, and Scots Guards, and the infantry attack by the French was broken up by Allied cavalry, in badly controlled charges which resulted in many losses to the allies. Napoleon's only option left was an all-out assault on the Allied centre. Wellington's reorganisation of his line was taken as the prelude to retreat, and waves of French cavalry attacked the Allies, which drove them into scattered defensive groupings ('squares'). This type of massed cavalry attack relied almost entirely on psychological shock for effect. Close artillery support could disrupt infantry squares and allow cavalry to penetrate; at Waterloo, however, co-operation between the French cavalry and artillery was not impressive. The French artillery did not get close enough to the Anglo - allied infantry in sufficient numbers to be decisive.

Napoleon's tactical skills are deemed to have been inferior to his skills as a strategist according to historians - coordination of the various branches of the French army at Waterloo was haphazard throughout, and at this moment decisively lacking. The squares held, the spaces between them protected by remnants of the Allied cavalry, and gradually the French cavalry assault, obliged to charge uphill through muddy terrain crisscrossed by sunken roads, petered out. The Prussians had begun driving through Napoleon's outposts, and it was now clear that the Prussians had fought their way through to the battlefield.

Napoleon made a last attempt to smash Wellington's centre before his two enemies could achieve any kind of linkage. At about six in the evening, the farmhouse of La Haye Sainte, linchpin of the Allied front, was finally taken. Wellington redrew the remnants of his front and prepared for the final assault; he did not know that the dark uniforms visible in the distance were the forces of Blücher rather than those of Grouchy. Napoleon sent forward the Old Guard, held in reserve to provide the decisive blow, and it branched out in a two-pronged attack to finish off what Napoleon believed to be an Allied army on the verge of annihilation. But Wellington had prepared a large scale ambush for the Guard; they ran into local counter attacks and enfilade fire from British infantry, hidden behind slopes. Unprepared and completely outnumbered, the Guard faltered, was checked, and triggered a French panic.

Wellington ordered an advance of the Allied line, just as the Prussians were overrunning the French positions to the east, and what remained of the French army abandoned the field in disorder. Wellington and Blücher met at the inn of La Belle Alliance, on the north – south road which bisected the battlefield, and it was agreed that the relatively rested Prussians should pursue the retreating French army back to France.

Wellington's army had held off the French attacks for several hours before Blücher's arrival, but there is still debate about whether the Allied victory would have been so crushing had it not been for the arrival of the Prussian Army. A third of Napoleon's army, under Marshal Grouchy, were engaged against the Prussians at Wavre some miles to the east, while 50 000 under Blücher attacked the French right. Considering these factors, and the fact that about a third of Wellington's army were German, one German historian in the 1990s went so far as to describe Waterloo as a "German Victory".

Many later attempts, some of them made to Wellington in person, also suggested that, by his own standards, Waterloo had been chaotic. But Wellington always maintained that his strategy had been clear from the beginning. He wanted to hold his position against everything Napoleon could bring against it, and to counter - attack the positions of the French at the right time, with the aim of ending the battle, a plan he had achieved. He had agreed to make a stand at Mont Saint Jean only on condition the Prussians would march west to link up with him, and he received only late in the day information that the Prussians were in fact making inroads on the French right.

On 22 June, the French Emperor abdicated again, and was transported by the British to Saint Helena, an island in the Atlantic. Waterloo marked the end of the Napoleonic Wars and was included in the classic work The Fifteen Decisive Battles of the World (1851) by Sir Edward Shepherd Creasy. The Treaty of Paris was signed on 20 November 1815.

Wellington entered politics again in 1819, when he was appointed Master - General of the Ordnance in the Tory government of Lord Liverpool. In 1827 he was appointed Commander - in - Chief of the British Army. He retained the position until his death.

Along with Robert Peel, Wellington became an increasingly influential member of the Tory party, and in 1828 he became Prime Minister of the United Kingdom.

During his first seven months as prime minister he chose not to live in the official residence at 10 Downing Street, finding it too small. He moved in only because his own home, Apsley House, required extensive renovations. During this time he was largely instrumental in the foundation of King's College London.

As prime minister, Wellington was conservative, fearing the anarchy of the French Revolution would spread to England. The highlight of his term was Catholic Emancipation; the granting of almost full civil rights to Catholics in the United Kingdom. The change was forced by the landslide by-election win of Daniel O'Connell, an Irish Catholic proponent of emancipation, who was elected despite not being legally allowed to sit in Parliament. The Earl of Winchilsea accused the Duke of, "an insidious design for the infringement of our liberties and the introduction of Popery into every department of the State". Wellington responded by immediately challenging Winchilsea to a duel. On 21 March 1829, Wellington and Winchilsea met on Battersea fields. When it came time to fire, the Duke took aim and Winchilsea kept his arm down. The Duke fired wide to the right. Accounts differ as to whether he missed on purpose; Wellington, noted for his poor aim, claimed he did, other reports more sympathetic to Winchilsea claimed he had aimed to kill. Winchilsea did not fire, a plan he and his second almost certainly decided upon before the duel. Honour was saved and Winchilsea wrote Wellington an apology. In the House of Lords, facing stiff opposition, Wellington spoke for Catholic Emancipation, giving one of the best speeches of his career. He had grown up in Ireland, and later governed it, so had some understanding of the grievances of the Catholic communities there. The Catholic Relief Act 1829 was passed with a majority of 105. Many Tories voted against the Act, and it passed only with the help of the Whigs.

The nickname "Iron Duke" originates from this period, when he experienced a high degree of personal and political unpopularity. Its repeated use in Freeman's Journal throughout June 1830 appears to bear reference to his resolute political will, with taints of disapproval from its Irish editors. His residence at Apsley House was targeted by a mob of demonstrators on 27 April 1831 and again on 12 October, leaving his windows smashed. Iron shutters were installed in June 1832 to prevent further damage by crowds angry over rejection of the Reform Bill, which he strongly opposed. These events are commonly thought to be the origin of his nickname.

Wellington's government fell in 1830. In the summer and autumn of that year, a wave of riots, the Swing Riots, swept the country. The Whigs had been out of power for most years since the 1770s, and saw political reform in response to the unrest as the key to their return. Wellington stuck to the Tory policy of no reform and no expansion of suffrage, and as a result lost a vote of no confidence on 15 November 1830. He was replaced as Prime Minister by Earl Grey.

The Whigs introduced the first Reform Bill whilst Wellington and the Tories worked to prevent its passage. The bill passed in the British House of Commons, but was defeated in the House of Lords. An election followed in direct response, and the Whigs were returned with an even larger majority. A second Reform Act was introduced, and defeated in the same way, and another wave of near insurrection swept the country. During this time, Wellington was greeted by a hostile reaction from the crowds at the opening of the Liverpool and Manchester Railway. The Whig Government fell in 1832 and Wellington was unable to form a Tory Government partly because of a run on the Bank of England. This left King William IV no choice but to restore Earl Grey to the premiership. Eventually the bill passed the House of Lords after the King threatened to fill that House with newly created Whig peers if it were not. Wellington was never reconciled to the change; when Parliament first met after the first election under the widened franchise, Wellington is reported to have said "I never saw so many shocking bad hats in my life".

Wellington was gradually superseded as leader of the Tories by Robert Peel, whilst the party evolved into the Conservatives. When the Tories were returned to power in 1834, Wellington declined to become Prime Minister and Peel was selected instead. However, Peel was in Italy at that time and for three weeks in November and December 1834, Wellington acted as interim leader, taking the responsibilities of Prime Minister and most of the other ministries. In Peel's first cabinet (1834 – 1835), Wellington became Foreign Secretary, while in the second (1841 – 1846) he was a Minister without Portfolio and Leader of the House of Lords.

Wellington retired from political life in 1846, although he remained Commander - in - Chief of the Forces, and returned briefly to the spotlight in 1848 when he helped organise a military force to protect London during that year of European revolution. Retaining the CiC title was a mistake for Wellington, as the army was in severe need of reforms and modernisation that he no longer had the energy to implement. The Conservative Party had split over the Repeal of the Corn Laws in 1846, with Wellington and most of the former Cabinet still supporting Robert Peel, but most of the MPs led by Lord Derby supporting a protectionist stance. Early in 1852 Wellington, by then very deaf, gave Derby's first government its nickname by shouting "Who? Who?" as the list of inexperienced Cabinet Ministers was read out in the House of Lords.

Wellington died, aged 83, of the after effects of a stroke culminating in a series of epileptic seizures, on 14 September 1852, at Walmer Castle — his honorary residence as Lord Warden of the Cinque Ports, which he enjoyed and at which he hosted Queen Victoria. Although in life he hated travelling by rail (after witnessing the death of William Huskisson, one of the first railway accident casualties), his body was then taken by train to London, where he was given a state funeral — one of only a handful of British subjects to be honoured in that way (other examples are Lord Nelson and Winston Churchill) — and the last heraldic state funeral to be held in Britain. At his funeral there was hardly any space to stand because of the number of people attending, and the effusive praise given him in Tennyson's "Ode on the Death of the Duke of Wellington" attests to his stature at the time of his death. He was buried in a sarcophagus of luxulyanite in St Paul's Cathedral next to Lord Nelson.

Wellington's casket is decorated with banners which were made for his funeral procession. Originally, there was one for Prussia, which was removed during World War I and never reinstated.

There is a lengthy account of his death, Lying in State and Funeral in Joseph Drew's biography of Wellington.

Wellington always rose early — he "couldn't bear to lie awake in bed" once awake — even if the army was not on the march. Even when he returned to civilian life after 1815, he slept in a camp bed, reflecting his lack of regard for creature comforts — it remains on display in Walmer Castle. General Miguel de Álava complained that Wellington said so often that the army would march "at daybreak" and dine on "cold meat", that he began to dread those two phrases. While on campaign, he seldom ate anything between breakfast and dinner. During the retreat to Portugal in 1811, he subsisted, to the despair of his staff who dined with him, on "cold meat and bread". He was, however, renowned for the quality of the wine he drank and served, often drinking a bottle with his dinner — not a great quantity by the standards of his day.

He took up high - technology and mechanical innovations and was one of the first British soldiers to employ shrapnel shells and congreve rockets; he was disappointed with the latter, as they were wildly inaccurate. He employed a full time officer to decrypt intercepted French messages. Conversely, although well organised, his supply trains comprised pack mules and ox carts with ungreased axles, plus cargo boats, if rivers could be used.

He rarely showed emotion in public, and often appeared condescending to those less competent or less well born than himself (which was nearly everyone). However, Álava was a witness to an incident just before the Battle of Salamanca. Wellington was eating a chicken leg while observing the manoeuvres of the French army though a spyglass. He spotted an overextension in the French left flank, and realised he could launch a successful attack there. He threw the drumstick in the air and shouted "Les français sont perdus!" ("The French are lost!"). Another time, after the Battle of Toulouse, when an aide brought him the news of Napoleon's abdication, he broke into an impromptu flamenco dance, spinning around on his heels and clicking his fingers.

Despite his famous stern countenance and iron handed discipline (he was said to disapprove of soldiers cheering as "too nearly an expression of opinion"), Wellesley cared for his men; he refused to pursue the French after the battles of Porto and Salamanca, because of the inevitable cost to his army in pursuing a broken enemy through rough terrain. The only time he ever showed grief in public was after the storming of Badajoz; he cried at the sight of the British dead in the breaches. In this context, his famous dispatch after the Battle of Vitoria calling them the "scum of the earth" can be seen to be fuelled as much by disappointment at their breaking ranks as by anger. He expressed his grief openly the night after Waterloo before his personal physician, and later with his family; unwilling to be congratulated for his victory he broke down in tears, his fighting spirit diminished by the high cost of the battle and great personal loss.

Viva Montgomerie, niece to the third Duke of Wellington, relates an anecdote that Holman, valet to the duke, often recalled how his master never spoke to servants unless he was obliged to, preferring instead to write his orders on a note pad on his dressing table. Holman incidently was said to greatly resemble Napoleon.

In 1824 Wellington received a letter from a publisher offering to refrain from issuing an edition of the rather racy memoirs of one of his mistresses, Harriette Wilson, in exchange for financial consideration. The Duke promptly returned the missive, after scrawling across it,"Publish and be damned".

He was also a remarkably practical man, who spoke concisely. In 1851, when it was discovered that there were a great many sparrows flying about in the Crystal Palace just before the Great Exhibition was to open, his advice to Queen Victoria was "Sparrowhawks, ma'am".

Wellington has often been portrayed as a defensive general, even though many, perhaps most, of his battles were offensive (Argaum, Assaye, Oporto, Salamanca, Vitoria, Toulouse). But for most of the Peninsular War, where he earned his fame, his troops lacked the numbers for an attack. Also, the Iberian peninsula provided excellent defensive terrain and he was never slow to take advantage of it.

Much of Wellesley's tactics were dictated by politics, supply, or finance. Being merely a general in the field, he had to deal with the vagaries of an unstable government at home, the Portuguese government, various Spanish Juntas, guerrilleros, and warlords. Also, the problem of supply in the barren peninsula was a dire one. The French did not bother to deal with it, and simply looted whatever supplies they needed. Wellesley, needing the goodwill of the populace, was required to bring in his supplies from elsewhere (especially wheat from America) and transport them to his troops in the field. This supply line was his ever present Achilles' heel, and often he was forced to either retreat or assume a defensive position when his line of supply was threatened.

In his defensive battles, he showed an understanding of defensive tactics almost unmatched. He, almost alone of the Napoleonic commanders, realised the use of a reverse slope defence, and made use of one whenever he could, to conceal his numbers and protect his men from artillery. Still, he rarely missed an opportunity to counter - attack, and many French columns found themselves cut up by musket volleys, then attacked with bayonets.

Wellesley could be very aggressive. His river crossing at Oporto was a gamble; and only the mistake of a subordinate officer allowed any of Soult's army to escape. On the attack also, he showed a clear understanding of tactics and terrain: at the Battle of Vitoria, he led a massive, well coordinated attack in four columns from three directions, almost destroying the French army, forcing them to abandon all their baggage and supplies and all but one of their 138 guns.

Still, he had to be very cautious. Besieged at the Lines of Torres Vedras, when Masséna's army was threatening Lisbon, Wellesley often stood on a parapet, surveying the French army with a telescope, muttering "I could whip them, but it would take 10,000 men, and as this is the only army England has, it behoves me to take care of it".

The total number of French troops in Spain always heavily outnumbered the available number of British and Portuguese, although most French soldiers were used for garrisoning the rebellious population. However, it was always possible for the French command to abandon some region, as they did after Salamanca, in order to concentrate a larger army than the British; Wellington was therefore always cautious during his incursions into Spain, with the great exception of 1813.

In the campaign leading up to the Battle of Vitoria, he was cut off from his supply line to Lisbon, so he re-established one on the north coast of Spain, throwing the French front line troops back upon their reserves.

Wellington's sieges achieved mixed results, with the Siege of Burgos being probably his worst defeat. Most of his sieges were in India, against Indian armies of worse training, arms, and morale than the French; he may have been overconfident at Burgos. Wellington had to retake the frontier fortresses (like Almeida) several times, because the French were equally successful in capturing them from the Allied garrisons. Also, he did not have the time for lengthy, Vauban - style sieges, because the French would have been able to gather up relieving forces. Hence, his brief and bloody, though successful, assaults on Ciudad Rodrigo and on Badajoz.

He disliked his cavalry commanders. He wrote a famous letter on 18 July 1812, accusing the cavalry of being unable to manoeuvre except on Wimbledon Common, and of always charging in a body, instead of forming in two lines — one to charge and one as a reserve. Of course, until 1815, he was denied the talents of the brilliant Henry Paget because of the family feud between them.

He acted as his own head of intelligence, and closely supervised both the supplying and the payment of his troops.

Much of his energy was diverted to political aims: shoring up his support in the British and Spanish governments, lobbying for his choice of officers, and cultivating the cooperation of the Portuguese and Spanish populations. While the French army alienated the latter by seizing their food and shooting anyone who resisted them, Wellington imported most of his food from abroad, paid cash for what he needed locally, and exercised strict discipline over his troops, regularly hanging men for looting, rape, murder, or desecration of religious sites. The locals repaid him with obedience, enlistment and information on French movements. In particular, the guerrilleros (partisans) operated in fairly close cooperation with British troops against the French, especially in their attacks on French couriers, and the passing of the captured French dispatches to Wellington.

As a general, Wellington is often compared to the 1st Duke of Marlborough, with whom he shared many characteristics, chiefly a transition to politics after a highly successful military career.

In September 1805, the then Major - General Wellesley, newly returned from his campaigns in India and not yet particularly well known to the public, reported to the office of the Secretary for War to request a new assignment. In the waiting room, he met Vice - Admiral Horatio Nelson, already a legendary figure after his victories at the Nile and Copenhagen, and who was briefly in England after months chasing the French Toulon fleet to the West Indies and back. Nelson began a conversation which Wellesley found "almost all on his side in a style so vain and silly as to surprise and almost disgust me". Nelson left the room to inquire who the young general was, and on his return switched to a very different tone, discussing the war and British policies as between equals. This was the only time that the two men met; Nelson was killed at his great victory at Trafalgar just seven weeks later. Some 30 years later, Wellington recalled the conversation and claimed "I don't know that I ever had a conversation that interested me more".