This miniature is a copy on a smaller scale of a drawing in the Royal Library (RCIN 452421) attributed to the artist Richard Cosway. The Duke is wearing the robe and star of the Order of the Garter.

Richard Cosway (1742-1821), the artist of the original, was appointed official miniature painter to George, Prince of Wales, William's older brother, in 1786 and general advisor for the decoration of Carlton House, the Prince's residence in London.

The miniature is set in a gold locket with light brown hair in the back mounted on opaque milk glass over gold rays, secured with pearls and a pearl anchor.