Trained by François de Troy in a tradition of rigorous seventeenth-century classicism, Grimou brought to the warm palette and considered composition of his master a 'certain audacity of handling' that presaged developments in French painting of the eighteenth-century. As Chardin would a generation later, Grimou looked to Dutch painters of the Golden Age for inspiration, and the deep chiaroscuro of the present picture is indepted to Rembrandt. While he is famed for genre scenes peopled with soldiers and musicians, his vibrant intimiste portrait half-lengths exerted a strong influence on Fragonard, manifested in the latter's celebrated portraits de fantaisie. Fragonard's fascination with Grimou's intense style extended to pastiches such as the Portrait of a Girl in the Dulwich Gallery, London.
The signature and date suggest that this is Grimou's prototype of this portrait. Another version, unsigned but of the same dimensions and composition, was sold in Paris, Hôtel Drouot, 5 march 1986, lot 101, as a work Attributed to Grimou. The Drouot picture may be the copy painted in Bourges by Françoise de Cambry, once in the collection of Madame de la Frémoire, that is mentioned in a note on the reverse.
The presumed sitter belonged to a family with close ties to the French Royal Court. The duc de Caumont-Laforce was the cousin of Admiral Amblimont, who served on the American side in the War of Independence, and was connected by marriage to General Thomas Sumter (after whom Fort Sumter is named), whose descendants were in turn connected by marriage to the vicomtes de Fontenay, in which line the portrait is believed to have descended.