George III has had no reason to complain of modern historians. He has been cleared of the 'taint' of madness (though I had never realised it was a taint) and instead suffered from porphyria, arsenic poisoning or both. Romney Sedgwick cleared him of the charge of being backward and Namier of being a monster of guile. Jack Brooke showed that he had no absolutist tendencies and put paid to the 'George, be a king' nonsense. The recent exhibition at the Queen's Gallery in Buckingham Palace showed George to be a man of taste, devoted to music, books and painting, and with a more than common interest in science and technology. Only in one place do old suspicions linger – in the Thirteen Colonies or, if you prefer an update, the United States of America. When Queen Elizabeth paid a visit to California in 1983 to commemorate the 200th anniversary of American Independence, she was...