Matriculated at St.Andrew's 25 January 1706, he entered the Navy in 1707. One of the first to join the rising in August 1715 for the restoration of the House of Stuart, he was consequently attainted of high treason on 17 February 1716, but escaped to Brittany.
As his Jacobite actions brought disgrace upon the family, his father procured an Act of Parliament to divert his titles and estates from the heir to his next son, Lord James Murray. However, on 1
February 1717, William was created Duke of Rannoch by James III, the titular king. Returning to Scotland with the Spanish force, he was defeated at the battle of Glenshiel on 18 June 1719. He again escaped, though 2,000 pounds Stirling was offered for his capture. In October 1734 he "had been a long prisoner for debt" at Paris.
After 26 years he accompanied the Chevalier St.George to Scotland, on whose behalf he unfurled the Royal Standard at Glenfinnan on 19 August 1745. Tullibardine took Blair Castle, his own family's seat, by force from his own brother. He accompanied the Young Pretender into Scotland
and was intimately identified with his cause.
After the battle of Culloden, he surrendered himself on 27 April 1746 and being very ill, was committed to The Tower of London. There he died unmarried on 9 July 1746 of a stoppage of urine, and was buried in the Chapel of The Tower.

Source: Leo van de Pas