William was born on 21st August 1765, third son of George III and Queen Charlotte. He had a naval career, served at the relief of Gibraltar and was stationed in the West Indies and Nova Scotia. He was a friend of Admiral Nelson. In 1784 he was created Duke of Clarence and St Andrews and Earl of Munster and in 1811 was appointed Admiral of the Fleet. By the actress Dorothea Bland, known as 'Mrs Jordan' he had ten children who bore the surname of FitzClarence.
He succeeded to the throne on the death of his brother George IV in 1830, as the second son of George III, Prince Frederick Duke of York, had died in 1827 without a son.
He married Princess Adelaide of Saxe-Meiningen at Kew Palace on 13th July 1818. They had no surviving children.
William IV and Queen Adelaide were crowned on 8th September 1831. The doors of the Abbey opened at 4.00 am. At 10.15 am the coronation procession left St James' Palace, the King dressed in an admiral's uniform and the Queen in a white and gold dress. For the first time a special lavishly furnished annexe had been built outside the west front of the Abbey to marshal the processions. The royal party arrived at 11.00am and the ceremony finished at 3.00pm. There was no usual coronation banquet as the King decided it was too expensive.
He died at Windsor Castle on 20th June 1837 and his niece Victoria succeeded him. He was buried at St George's chapel. Queen Adelaide died on 2nd December 1849 and was buried with him.
Oxford Dictionary of National Biography, 2004
Music for William IV's Coronation, 1831 (PDF 2,115KB)
British Royal and State funerals.... by M. Range, 2016
National Portrait Gallery, London