Mercier could turn a Watteau Fête Champêtre into a fashionable group portrait. Here he shows the Prince playing a sonata, accompanied by his sisters: Princess Anne, a pupil of Handel, on the harpsichord, and Princess Caroline on the mandora. The painting depicted on the wall is one of the set of Pellegrinis that is hanging in the gallery opposite (cats 228 – 231), and the mirror also survives to this day, hanging on the wall to the right (cat. 110). Probably painted for Frederick, Prince of Wales Cat. 255