George III (1738-1820)and Queen Charlotte observing the roasting of an ox at Windsor, part of celebrations to mark the king's Diamond Jubilee in 1810. Accompanied by the queen and several of their children, the royal family watched from an erected pavilion and were served slices of beef with plum pudding. The festivities at Windsor were among many held throughout the country to mark the fifty year reign of this popular monarch. Shortly afterwards, George's favourite daughter, Amelia fell ill and died. The shock brought on mental derangement (now thought to be caused by porphyria) and in 1811, the Prince of Wales was appointed Prince Regent.