Dando-Collins describes Caligula as a “changeable, unpredictable and contradictory” leader during his debauched rule of Rome from 37 to 41 A.D., a period during which he made deranged claims of his own divinity. “He was sometimes cowardly and unable to own up to a mistake,” he writes. “He considered himself a scholar and master manipulator of words. ... (He) was driven by self-gratification and paranoia and ruled on impulse.”