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.
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'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.
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 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.
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.