Rosalba Carriera was the most celebrated portraitist in eighteenth-century Venice. Her contemporaries recognized her achievement by admitting her to the Accademia di San Luca, Rome, in 1705; to the Accademia Clementina, Bologna, in 1720; and to the Académie Royale, Paris, in 1721. While in Paris, she portrayed Louis XV as a child. She also received commissions from the courts of Modena, Vienna, and Dresden. Rosalba worked in pastel and as a miniaturist, in watercolor and gouache, and, partly because these materials are fugitive and the display of the objects is therefore restricted, she had previously been represented in the Museum by a single miniature of a gentleman in armor.

Gustavus Hamilton (1710–1746) was an Irish aristocrat who visited Venice twice, in the carnival seasons of 1730 and of 1731. He probably commissioned this work, and two variants now in English private collections, through Owen Swiny, an Irish impresario who was the artist's agent and was also known as McSwiney. In addition to stylish linen, damask, and a fur-trimmed coat, Viscount Boyne wears carnival costume: a lace bautta, or veil, and a half mask, cocked under a tricorne hat. The pastel, which descended in the family of a close personal friend of the sitter, is exceptional for its faultless state of preservation.