Aged Roman emperor Claudius begins writing his memoirs. They begin during the reign of Emperor Augustus and his devious wife, Empress Livia, the grandmother of our hero.
Evil Livia continues to spin her web in order to insure that her son Tiberius succeeds Augustus as Emperor of Rome.
Livia is determined to see her exiled son, Tiberius, succeed Augustus as emperor and uses blackmail and murder to end his banishment. Tiberius finally returns to Rome as heir to the throne but must wait on Augustus to die. Livia, however, is tired of waiting.
Livia gets rid of one last rival to Tiberius's path to the throne, Postumus-the son of Augustus' daughter, Julia. Postumus reveals the depths of Livia's depravity to her stammering and lame grandson, Claudius. Claudius has been pretending to be a half-wit in order to survive the various intrigues at court.
Livia's crimes are revealed to Augustus who writes a new will naming Postumus not Tiberius as his heir. Livia then slowly poisons her husband and upon his death substitues a will naming Tiberius heir to the throne.
Tiberius is Emperor but the murder of the popular Germanicus (brother of Claudius) leads to a confrontation between his supporters and those of Aggrippina.
Tiring of being emperor, Tiberius withdraws into a life of perverted hedonism on the Isle of Capri. His sadistic henchman, Sejanus, controls things in Rome for him. Meanwhile, the aging Livia regrets putting her son on the throne and reveals all to grandson Claudius whom she predicts will become emperor someday. Livia then makes Claudius promise to make her a goddess upon his ascension to the throne so that she won't have to spend eternity in Hades for her crimes.
Tiberius, ever paranoid, begins a purge of his enemies in Rome including Sejanus. He then names young Caligula as his heir not because of merit but because he knows that Caligula is a monster who will make him look good by comparison.
Tiberius dies and Caligula succeeds him as Emperor of Rome. At first the new emperor is extremely popular with the people and treated like a rock star but his true nature gradually emerges. Caligula descends into madness and declares that he is now a god. That's bad news for all the mortals living in the Roman Empire as an orgy of bloodletting begins.
Caligula's maniacal reign continues as he turns the palace into a brothel and gambling den and forces prominent ladies to staff the place. As things continue for the worse, a plot against Caligula's life emerges and he is assassinated by members of his own bodyguard who give the crown to Claudius, a witness to the assassination.
Claudius takes the throne of Rome and soon proves himself to be an able administrator. Unfortunately, he's also married to the unfaithful Messalina who will prove to be a huge embarassment for him in the coming years.
Claudius leads the Roman Army into battle in Britain. Meanwhile, on the homefront, his nymphomaniac wife Messalina is bedding down every man she can get her hands on.
Claudius is persuaded to marry Agrippinilla, a corrupt woman who covets the throne of Rome for her son, Nero. He then completes his memoirs knowing that according to prophecy Nero will succeed him and be the final Caesarian emperor of Rome.