Vitellia regards herself as the rightful successor as ruler of Rome. But now Tito is emperor and shows no sign of at least marrying her. Far worse: he loves a foreigner, Queen Berenice of Judea. Vitellia therefore wants to start a rebellion. She has caused Tito’s friend Sesto to fall in love with her and asks him to kill Tito. Sesto hesitates but his desire for Vitellia’s love is greater. When he leaves, Vitellia learns that Tito has broken off his engagement to Berenice. Vitellia is sure that Tito will marry her and calls off the rebellion. But she is mistaken: Tito chooses Servilia, Sesto’s sister. Once again, Vitellia is snubbed. Again she incites Sesto to rebellion. In the meantime Servilia has confessed to the Emperor that her heart belongs to Annio. Tito releases her. At last he chooses Vitellia as his bride. But Vitellia is unable to recall Sesto. The man he stabs in the darkness is not the Emperor. Sesto is arrested but Vitellia tells the truth in order to save Sesto’s life. In the end Tito forgives all his enemies, he also decides not to marry.