The sitter was the second son of Hans Willem (or William) Bentinck, 1st Earl of Portland (1649-1726), confidant and favourite of King William III. His mother was Portland's second wife, Jane Martha, Dowager Lady Berkeley, daughter of Sir John Temple, of East Sheen. He owned estates at Rhoon and Pendrecht in Holland and Terrington St. Clements in Norfolk and was created a Count of the Holy Roman Empire by the Emperor Charles VI in 1732. In 1733 he married Countess Charlotte Sophia (1715-1800), daughter and heiress of Anthony II, Count of Aldenberg and Sovereign Lord of Kniphausen and Varel, by his wife Princess Wilhelmina Maria of Hesse-Homburg. The elder son Christian suceeded as Sovereign Lord of Kniphausen and Varel in 1754 while Terrington St. Clements passed to the second, John (1737-1775). Both true to the Anglo-Dutch history of their family married, in 1760 and 1763 respectively, Mary and Renira, daughters of Jan Maximilien, Baron de Tuyll de Serooskerken, lord of Westbrock and Vleuten (1710?-1762), who, with his wife was portrayed by Liotard in 1756 (R. Loche and M. Roethlisberger, L'opera completa di Liotard, Milan, 1978, nos. 205-6): Liotard also made pastels of her sister, the Countess of Athlone and of her brother's wife (ibid., nos. 288-90) during his final visit to Holland in 1772-3.
Hitherto unpublished, this portrait corresponds closely with a pastel in the Huyssen van Kattendyke collection at the Hague (ibid., no. 187), which is signed and dated 1755. A pastel copy is owned by the descendants of the sitter's elder son at Kastel Middachten, De Steeg, while a copy in oil, which was sold in these Rooms, 29 March 1968, lot 38, is now in the Rijksmuseum, no. A.4155 (for details see ibid., under no. 187).
The present picture no doubt is of the same year as the pastel. Partly because his native Geneva offered too limited a forum for his talents, but, equally one suspects on account of an instinctive search for challenges, Liotard was one of the most widely travelled artists of his century. In 1755 he left England, after an immensely successful and remunerative two years visit, for Holland, where a year later he was to marry the daughter of an emigrée from France, before returning by way of Paris to Geneva. Liotard, almost immediately on his arrival, received commissions from influential Dutch families, including the de Tuylls with whom Bentinck was evidently on close terms, to judge from the subsequent marriage of his elder sons to their daughters. Through their mother the latter were closely related to two other sitters of Liotard's first Dutch visit, the enchanting seven-year-old Maria-Frederike van Reede-Athlone and Luisa Isabella, Countess of Athlone, the portrait of whom was formerly in the Aldenberg-Bentinck collection (ibid., nos. 191 and 192). Four of Bentinck's sisters married Englishmen, and the son of one, James Hamilton, 4th Earl of Clanbrassil was in turn to be a patron of Liotard during his second English sojourn in 1772-4.
This portrait, characteristically direct in observation, exemplifies the qualities that distinguish Liotard from most contemporary fashionable portraitists, and explains why a parallel with the few portraits of Stubbs has been invoked.
The loan of this picture has been requested for the exhibition Liotard to be curated by Marcel Roethlisberger and Paul Lang, which is to be held at the Musée de l'art et histoire, Geneva, 1 March-15 May 2000.