No easily accessible book which lists the emperors (of which there are very many, thanks to the vicissitudes of the empire itself) in alphabetical order for easy reference and in which a reasonably full biographical account of each, with references, has been available. Here it is. This biographical dictionary runs from Caesar's seizure of power in 49BC to AD602, when the dynasty of Justinian and his successors ended (rather bloodily in a mutiny) and the true Byzantine, much more entirely Greek, character of the empire finally emerged. It includes an account of the way the empire evolved constitutionally. Up to the settlement of Augustus powerful men were almost sleepwalking into monarchy and trying to stretch the constitutional envelope to enable power to be wielded without a naked revival of the hated institution of kingship. From that time, Roman politics became highly fractured, and men bent on gaining control of the levers of government emerged with increasing frequency. Hereditary succession became the norm and then disappeared. In Rome, unlike Medieval Europe, the natural succession of son to father became a rarity and, when it did occur, was usually a disaster. It was only in its Byzantine mutation after 610 that dynastic succession became more standardized, but even then it was mediated by assassination. Of the 198 figures featured here, 101 were killed. Julius Caesar observed: 'Which death is preferable to every other? The unexpected.'