The sitter has traditionally been identified as Lord John Murray, the eldest son of John Murray, 2nd Marquis and 1st Duke of Atholl, and half-brother of the Jacobite leaders, William Murray, Marquis of Tullibardine, and Lord George Murray. Murray was elected M.P. for Perth four times between 1734 and 1754. In 1745 he was appointed Colonel of the 42nd Highlanders, a regiment to which he was devoted and became General of in 1770. He marched at the head of the many highlanders disabled at Ticonderoga in 1758, and successfully put their claims before the Chelsea board.
Ramsay painted two other portraits of Murray in 1743 and 1759 (both now in private collections, A. Smart, Ed. J. Ingamells, op. cit., nos. 389-190, pls. 149 and 500) and while the identification of the sitter in the present portrait dates from at least 1905 (when the picture was sold at the Gallotti sale, Paris), comparison with the other known portraits of Murray is not conclusive.