William IV (William Henry; 21 August 1765 – 20 June 1837) was King of the United Kingdom of Great Britain and Ireland and King of Hanover from 26 June 1830 until his death in 1837. The third son of George III, William succeeded his elder brother George IV, becoming the last king and penultimate monarch of the United Kingdom's House of Hanover.
William served in the Royal Navy in his youth, spending time in British North America and the Caribbean, and was later nicknamed the "Sailor King". In 1789, he was created Duke of Clarence and St Andrews. Between 1791 and 1811, he cohabited with the actress Dorothea Jordan, with whom he had ten children. In 1818, he married Princess Adelaide of Saxe-Meiningen. In 1827, he was appointed Britain's Lord High Admiral, the first since 1709.
As his two elder brothers died without leaving legitimate issue, William inherited the throne when he was 64 years old. His reign saw several reforms: the Poor Law was updated, child labour restricted, slavery abolished in nearly all of the British Empire, and the electoral system refashioned by the Reform Act 1832. Although William did not engage in politics as much as his brother or his father, he was the last British monarch to appoint a prime minister contrary to the will of Parliament. He granted his German kingdom a short-lived liberal constitution. William had no surviving legitimate children at the time of his death, so he was succeeded by his niece Victoria in the United Kingdom and his brother Ernest Augustus in Hanover, ending the 123-year personal union between the two countries.
William was born in the early hours of the morning on 21 August 1765 at Buckingham House, the third child and son of King George III and Queen Charlotte. He had two elder brothers, George, Prince of Wales, and Prince Frederick (later Duke of York and Albany), and was not expected to inherit the Crown. He was baptised in the Great Council Chamber of St James's Palace on 20 September 1765. His godparents were the King's siblings: Prince William Henry, Duke of Gloucester and Edinburgh; Prince Henry (later Duke of Cumberland and Strathearn); and Princess Augusta, Hereditary Duchess of Brunswick-Wolfenbüttel.
William spent most of his early life in Richmond and at Kew Palace, where he was educated by private tutors. At the age of thirteen, he joined the Royal Navy as a midshipman, in Admiral Robert Digby's squadron. For four years the lieutenant of his watch was Richard Goodwin Keats, with whom he formed a life-long friendship and whom he described as the one to whom he owed all his professional knowledge. He was present at the Battle of Cape St Vincent in 1780, when the San Julián struck her colours to his ship. His experiences in the navy seem to have been little different from those of other midshipmen, though in contrast to other sailors he was accompanied on board ship by a tutor. He did his share of the cooking and got arrested with his shipmates after a drunken brawl in Gibraltar; he was hastily released from custody after his identity became known.
William served in New York during the American War of Independence, making him the only member of the British royal family to visit America up to and through the American Revolution. While William was in America, George Washington approved a plot to kidnap him, writing:
The spirit of enterprise so conspicuous in your plan for surprising in their quarters and bringing off the Prince William Henry and Admiral Digby merits applause; and you have my authority to make the attempt in any manner, and at such a time, as your judgment may direct. I am fully persuaded, that it is unnecessary to caution you against offering insult or indignity to the persons of the Prince or Admiral...
The plot did not come to fruition; the British heard of it and assigned guards to William, who had until then walked around New York unescorted. In September 1781, William held court at the Manhattan home of Governor James Robertson. In attendance were Mayor David Mathews, Admiral Digby, and General Oliver De Lancey.
William became a lieutenant in 1785 and captain of HMS Pegasus the following year, during which he spent time in the colonies of Newfoundland and Nova Scotia. Later in 1786, he was stationed in the West Indies under Horatio Nelson, who wrote of William, "in his professional line, he is superior to two-thirds, I am sure, of the [naval] list; and in attention to orders, and respect to his superior officer, I hardly know his equal." The two were great friends, and dined together almost nightly. At Nelson's wedding, William insisted on giving the bride away. After touring Quebec in 1787, he was, the next year, given command of the frigate HMS Andromeda and promoted to rear-admiral while commanding HMS Valiant in 1790.
William sought to be made a duke like his elder brothers, and to receive a similar parliamentary grant, but his father was reluctant. To put pressure on him, William threatened to stand for the House of Commons for the constituency of Totnes in Devon. Appalled at the prospect of his son making his case to the voters, the King created him Duke of Clarence and St Andrews and Earl of Munster on 19 May 1789, supposedly saying: "I well know it is another vote added to the Opposition." William's political record was inconsistent and, like many politicians of the time, cannot be ascribed to a single party. However, he allied himself publicly with the Whigs, as did his elder brothers, who were known to be in conflict with the political positions of their father.
William ceased his active service in the Royal Navy in 1790. When Britain declared war on France in 1793, he was eager to serve his country and expected to be given a command but was not, perhaps at first because he had broken his arm by falling down some stairs drunk, but later perhaps because he gave a speech in the House of Lords opposing the war. The following year he spoke in favour of the war, and expected a command after his change of heart; none came. The Admiralty did not reply to his request. He did not lose hope of being appointed to an active post. In 1798 he was made an admiral, but the rank was purely nominal. Despite repeated petitions, he was never given a command throughout the Napoleonic Wars. In 1811, he was appointed to the honorary position of Admiral of the Fleet. In 1813, he came nearest to involvement in actual fighting, when he visited the British troops fighting in the Low Countries. Watching the bombardment of Antwerp from a church steeple, he came under fire, and a bullet pierced his coat.
Instead of serving at sea, William spent time in the House of Lords, where he spoke in opposition to the abolition of slavery, which still existed in the British colonies. Freedom would do the slaves little good, he argued. He had travelled widely and, in his eyes, the living standard among freemen in the Highlands and Islands of Scotland was worse than that among slaves in the West Indies. His experience in the Caribbean, where he "quickly absorbed the plantation owners' views about slavery", lent weight to his position, which was perceived as well-argued and just by some of his contemporaries. In his first speech before Parliament he called himself "an attentive observer of the state of the negroes" who found them well cared for and "in a state of humble happiness". Others thought it "shocking that so young a man, under no bias of interest, should be earnest in continuance of the slave trade". In his speech to the House, William insulted William Wilberforce, the leading abolitionist, saying: "the proponents of the abolition are either fanatics or hypocrites, and in one of those classes I rank Mr. Wilberforce". On other issues he was more liberal, such as supporting moves to abolish penal laws against dissenting Christians. He also opposed efforts to bar those found guilty of adultery from remarriage.
William had an illegitimate son before 1791 whose mother is unknown; the son, also called William, likely drowned off Madagascar when HMS Blenheim sank or foundered in February 1807. Caroline von Linsingen, whose father was a general in the Hanoverian infantry, claimed to have had a son, Heinrich, by William in around 1790 but William was not in Hanover at the time that she claims, and the story is considered implausible by historians.