William Colyear, later 3rd Earl of Portmore, was the second but only surviving son of the Scottish nobleman Charles, 2nd Earl of Portmore (1700-1785), who was Member of Parliament for Wycombe (1726) and Andover (1727-30) and was a founding Governor of the Foundling Hospital, and his wife Juliana, widow of Peregrine, 3rd Duke of Leeds. He was styled Viscount Milsington on the death of his elder brother David in 1756. His sitter's paternal grandfather David Colyear (1657- 1730), who had been raised to the earldom in 1703, was a prominent General who fought in the Spanish War of Succession (1701-14) and was Commander-in-Chief of forces in Scotland (1710), a member of the Privy Council, and Governor of Gibraltar. His paternal grandmother Catherine (1657-1730), who was the daughter of Sir Charles Sedley, had previously been a mistress of King James II. His father, a great patron of the turf, whom Reynolds painted in 1758 (Mannings, op.cit., I, no. 397, II, fig. 355), was conspicous in society for his dress and was known as 'Beau Colyear' and Wraxall noted that 'when nearly 80 he retained his activity of body, with many personal graces, and the most polished manners'. Viscount Milsington went to Eton in 1754 and later to St. John's College, Cambridge. He succeeded as the 3rd Earl of Portmore in 1785 and married Mary (1753-99), second daughter of the 1st Earl of Rothes. He died in London in 1823. Sittings for this portrait are recorded in October and November 1759 and sittings for 'Lord Melsing. [sic] Dog' are recorded on the 27 October that year.
By the late 1750s, Reynolds, who had returned from a two year stay in Italy in 1752, and was settled in London by 1753, had established himself as the leading and most imaginative portrait painter in England. On his return from Italy, Reynolds breathed new life into the tradition of British portraiture infusing his commissions with a new sense of vitality, drama and a grandeur and this ability was soon recognised and greatly sought after. The versatility and imaginative force which he demonstrated in such portraits as his commanding full-length of Commodore Keppel, painted soon after his return from Italy (National Maritime Museum, London; Mannings, op.cit., I, no. 1037, pl. 10, II, fig. 70), and Captain Robert Orme (National Gallery, London; Mannings, op.cit., I, no. 1366, pl. 11, II, fig. 216) as well as in works on a smaller scale and of a less heroic character, led to an abundance of commissions from among the highest echelons of society. The demand for his services allowed him to increase his price for a standard bust-length portrait some fivefold by the end of the decade and his success was also reflected in his acquisition, in the summer of 1760, of a new studio, on the west side of Leicester Square, near the fashionable residential West End, which allowed him to meet his sitters in considerable style.
This picture is one of Reynolds' most engaging child portraits and one of the most successful works from the early part of his career. It shows the imagination and subtlety which he brought to bear in his portraiture, qualities which differentiated him from rival portrait painters in Britain. Reynolds manages to express the innocence of childhood with directness and simplicty without losing a sense of the sitter's elevated social position. In the catalogue to the 1986 exhibition at the Tate Gallery, Nicholas Penny commented that the portrait 'is typical of the engaging directness of presentation, freshness of handling and simplicity of both composition and colour favoured by Reynolds in the late 1750s... the colours a brilliant arrangement of brown black and white' and also admired Reynolds' exploitation of the device 'of rival pairs of eyes confronting us'. The portait, which shows the influence of the work of Rembrandt on the artist, can be compared to other Reynolds portraits of children from the 1750s such as those of Lady Charlotte Fitzwilliam of 1754 (private collection) and Lord George Grenville (private collection).