At the heart of this history of the Julio-Claudian dynasty are the lives of six men Julius Caesar, Augustus, Tiberius, Gaius Caligula, Claudius and Nero  men who mastered Rome and changed it from a democracy to a personal possession. It was no easy task: Caesar and Caligula were assassinated, Nero committed suicide and Claudius was poisoned. Only Augustus and Tiberius died natural deaths  and even that is uncertain. The Julio-Claudian saga has a host of other characters, from Cicero, the last great statesman of the Republic, to Livia, matriarch of the Empire; the passionate Mark Antony and the scheming Sejanus; and Agrippina, mother of Nero and sister of Caligula, who probably murdered her husband and in turn was killed by her son.