Jean Henri Masers de Latude (1725-1805) was born at Montagnac in Gascony and, after receiving a military education, went to Paris in 1748 to study mathematics. In an attempt to curry favour with Madame de Pompadour, he secretly sent her a box of poison and then informed her of a supposed plot against her life; but the ruse was discovered and he was imprisoned in the Bastille on 1 May 1749. He remained in prison, either the Bastille or Vincennes, until 1784, making a number of escapes but always being recaptured, and only finally gaining his freedom when a certain Mme Legros took up his case and launched a vigorous campaign on his behalf.

Following his release, he posed as a brave officer, a son of the Marquis de la Tude and a victim of the Pompadour's intrigues. In 1787 he published an account of his imprisonment, which was translated into English the same year. It is full of misrepresentations but enjoyed a great vogue during the French Revolution when Latude was lionized; he received a state pension, and in 1793 the convention compelled the Pompadour's heirs to pay him damages of 60,000 francs. He died in obscurity in Paris on 1 January 1805.

Edward S. Swinson was a London-based painter who seems to have specialized in portraits, exhibiting six at the Royal Academy between 1893 and 1902. Little is known of his work. The present picture was apparently exhibited at the Royal Institute of Oil Painters, but has not been traced in the catalogues for the years following its date of execution, 1906.