John Grant was the son of Patrick Grant of Glenlochy (1709-1783) and his wife Beatrix (1711-1780), and uncle of Sir Francis Grant, P.R.A. He studied for the English bar, then went out to Halifax, Nova Scotia with his brother Francis before going to live in Jamaica. He succeeded Thomas French as Chief Justice of Jamaica in 1783 until 1790. He married Margaret McLeod, daughter of Lord Bannatyne, who died in 1825. In 1786 he and his brother bought the estate of Kilgraston near Perth to which he retired in 1790. A half-length version of this picture was sold by E. Culme Seymour, Christie's, London, 21 November 1952, lot 2.