Born 6 May 1729, eldest son of Lord George Murray (attainted brother of second Duke) by his wife Amelia, only surviving child of James Murray of Glencarse and Strowan. As a boy ( 1745-6) held a captain's commission in Lord Loudon's regiment but never served.
In 1761 chosen as MP for Perth.
Succeeded to title on death of his uncle in 1764 but in order to clarify any doubts as to his succession petitioned King to confirm the title, which was done by House of Lords in Feb 1764.
Married his cousin Charlotte Murray, only surviving child of the 2nd Duke by whom he acquired sovereignty of Isle of Man. However quickly bowed to pressure to confirm sale of regalities of Island to English crown, an agreement that had been agreed to by his uncle, and in 1765 sold regalities for £70,000 but kept many other rights including that of nominating the Bishop.
Chosen a Scottish representative peer in 1764 and again in 1768. Died at Dunkeld 5 Nov 1774 (suicide).
By Lady Charlotte Murray had seven sons and four daughters -
John, 4th Duke of Atholl, was appointed Governor of Man in 1793.
-- died in infancy,
George, Archdeacon of Man and later Bishop of St. David's,
Henry - colonel of Manx Fencibles - buried Kirk Braddan
Charles, also at one time Archdeacon of man and later dean of Bockingham, Essex,
Charlotte, died unmarried
Amelia, first marriage to Thomas Ivie Cooke, army officer; 2nd to Sir Richard Gamon
Jane, married John Groset Muirhead of Breadisholme,
Mary, married Rev George Martin.
Dictionary of National Biography
S Walpole Land of Home Rule 1893 Chapter 13