As a young boy, future emperor Nero witnesses the mad Emperor Caligula kill his father and exile his mother. While in exile in the pontine islands, Agrippina, his mother, sees a vision telling her that her son can become emperor, but she will have to die first. She accepts the proposal. Back in Rome, Nero, now being raised by emperor Claudius after Caligula's death, Agrippina returns. She poisons Claudius' food and Nero becomes emperor. At first, Nero cuts taxes and introduces successful programs and invades Brittania. Soon he meets a beautiful slave named Claudia Acte, and marries her, throwing off his engagement with Claudius' daughter, Claudia Octavia, telling her she can marry someone she will be happy with. Heartbroken, she arrives at an island and kills herself. Nero enjoys being married to Claudia Acte, but soon he gradually goes mad with power and sets fire to Rome. He divorces Acte, and forces the citizens to watch hour long recitals, and at one of these, accidentally kills his new pregnant wife, Poppaea Sabina. He kills several members of the senate and orders his mother to be stabbed, where she says: "Strike the womb, for that is what bore him." Nero's madness soon causes a riot, causing himself to flee the city in disguise, and slit his wrists under the saddened embrace of Claudia Acte, his once passionate lover.
The movie in many ways tries to show Nero as a good soul gone mad, beginning as a brilliant young prince enduring injustice, then hailed enthusiastically at the beginning of his reign, implementing much-needed reforms and enjoying immense popularity. Half the film concentrates on Nero's teenage years and his love life with Acte.