In 1787 Reynolds painted the portrait of Lord Heathfield, who became a national hero for the successful defence of Gibraltar in the Great Siege from 1779 to 1783 against the combined forces of France and Spain. Heathfield is depicted against a background of clouds and cannon smoke, wearing the uniform of the 15th Light Dragoons and clasping the key of the Rock, its chain wrapped twice around his right hand. John Constable said in the 1830s that it was "almost a history of the defence of Gibraltar". Desmond Shawe-Taylor has claimed that the portrait may have a religious meaning, Heathfield holding the key similar to St. Peter (Jesus' "rock") possessing the keys to Heaven, Heathfield "the rock upon which Britannia builds her military interests".