This pastel dates from Liotard's last visit to England in 1773-4.
James Hamilton, 2nd Earl of Clanbrassil (1730-1798), a member of the Society of Dilettanti, an MP and a noted botanist, succeeded to the title in 1758. Mrs. Delaney, a cousin of his wife's, described him, shortly after this portrait was taken, as 'old for his age (having lost all his foreteeth), but he is tall, genteel, and very well bred'.
In 1774 he commissioned a second portrait from Liotard, together with a portrait of his wife. The pair was offered at Christie's, 6 July 1993, lot 184, both illustrated.