Ozias Humphry (1742-1810), King George III triptych. The central panel showing George III and the Prince of Wales reviewing the troops, circa 1797 (after William Beechey). Portraits of Queen Charlotte and a seated King George III (after Zoffany, circa 1771) adorn each side, hand-painted on ivory panels, signed lower right in the centre panel, original carved bone, mother of pearl and ivory frame, 41 x 63 cm overall