William IV lived from 21 August 1765 to 20 June 1837 and was King of the United Kingdom and of Hanover from 26 June 1830 until his death. William was the third son of King George III and younger brother and successor of King George IV: he was also the last king and penultimate monarch of the House of Hanover. The wider picture in Scotland at the time is set out in our Historical Timeline.
William was one of King George III's 15 children. As he had two older brothers, Prince George, Prince of Wales and Prince Frederick, Duke of York, William probably never expected to become king himself. At the age of 13 he joined the Royal Navy as a Midshipman, and took part in the Battle of St Vincent in 1780. During the American War of Independence he served in New York, and became the subject of an American kidnap plot approved by George Washington. The plot was discovered and foiled. William was promoted to Lieutenant in 1785 and Captain the following year when he was posted to the West Indies. Horatio Nelson 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."
In 1789 William forced George III to make him a Duke with a Parliamentary income, like his two older brothers. The king was initially reluctant because of the political opposition such a move would cause, but agreed when William threatened to run for the House of Commons for the constituency of Totnes in Devon if he didn't. William duly became the Duke of Clarence and St Andrews and the Earl of Munster.
The Duke of Clarence left the Royal Navy in 1790, with the rank of Rear Admiral. He hoped to return to active service during the war with France from 1793, but instead spent his time in the House of Lords, defending the debts of his brother George, Prince of Wales, and, amongst other things, arguing in favour of slavery in the colonies.
From 1791 the Duke of Clarence lived with the actress, Dorothea Bland, more usually known by her stage name of Mrs Jordan. Over the 20 years until their affair ended, the two would have 10 illegitimate children, who were given the surname "FitzClarence."
In 1811, the Duke of Clarence was appointed to the post of Admiral of the Fleet. Meanwhile, George III's eldest son, the Prince of Wales, only had one child, and when she died in 1817, the remaining unmarried sons of George III set out to do their duty and ensure the future of the dynasty. William's first choices as Duchess either turned him down or were rejected as unsuitable by George, Prince Regent. William then trawled through all the available Protestant princesses in Germany, eventually settling on Princess Adelaide of Saxe-Meiningen, a woman 27 years his junior. Princess Adelaide took on board William, his various debts, and his ten illegitimate children, and their marriage was apparently a happy one, although both their children were very short-lived.
In 1820 George IV succeeded to the throne, and when Frederick, Duke of York died in 1827, William became heir to the throne. William occupied himself during the 1820s as Lord High Admiral of the Navy, introducing a series of innovations, including the Navy's first steam-driven warship.
William IV succeeded to the throne in 1830, aged 64. His most notable success as King was the passing of the Reform Act 1832, which produced the first change in the way MPs had been elected in 500 years. Under the existing system, cities like Manchester and Birmingham had no seats in Parliament, yet somewhere like Old Sarum, with a total of seven voters, returned two MPs, usually appointed by the local landowner. At a time of high political drama the House of Commons passed the Reform Bill several times, each time finding it blocked by the House of Lords. In the end William had to threaten to create large numbers of peers supportive of reform to get the House of Lords to back down.
William IV died of heart failure at Windsor Castle in 1837, and was later buried there. Without legitimate offspring, the Crown of the United Kingdom passed to his 18 year old niece, Princess Victoria of Kent. Tradition prevented a woman from ruling Hanover, so the Hanoverian Crown went to William's brother, Prince Ernest Augustus, Duke of Cumberland. Although William IV's marriage had produced no offspring, there have been some notable descendents from his long relationship with Dorothea Bland. These include the leader of the Conservative Party, David Cameron, the TV presenter Adam Hart-Davis and the late actor, Oliver Reed.