Henry St John was a politician, diplomat and author. He served as secretary at war and secretary of state under Queen Anne, but was suspected of Jacobite sympathies and dismissed by her successor, George I. He was the author of The Idea of a Patriot King, which strongly influenced George III. In this pamphlet, Bolingbroke argued that Britain's balanced constitution could be preserved only if the monarch acted on patriotic principles, ruling in the interests of the nation at large and choosing upright and honest men as his ministers.

The miniature was probably painted by a follower of Christian Frederick Zincke (1683/4-1767). The sitter's apparent age of about fifty or more, and the style of wig and dress, suggest a date in the early 1730s.