While it has become common to question the sanity of world leaders, there have been some who unquestionably went around the bend. In these historical and psychological profiles, Scott Rank includes the Roman Emperor Caligula, Russia's Ivan the Terrible—who clubbed his son to death with his scepter—and Britain's King George III, who lost the American colonies and his mind. Here too are Uganda's Idi Amin, an army cook who became president; Bavaria's "Mad" King Ludwig II, patron of Richard Wagner and builder of fairy tale castles; and Louis VI, the French King who believed that he was made of glass.