Rome, first century AD

Act I

Emperor Tito is in love with Berenice of Judea, thus frustrating the plans of Vitellia, daughter of the former emperor of Rome (who had been deposed by the present Emperor Tito’s father Vespasian), to regain the throne as Tito’s consort. She persuades Sesto, Tito’s dearest friend and who is in love with her, to assassinate the emperor. But Tito has renounced Berenice—the Roman people want a Roman empress—and Vitellia calls off the plot.

Yet Tito chooses not Vitellia for empress, but Sesto’s sister Servilia. However, once he is made aware that Servilia is already in love with Sesto’s friend Annio, Tito forswears the idea of coming between the lovers. Vitellia, furious at being passed over (again) but unaware of Tito’s change of heart, instructs Sesto to kill the emperor immediately. As soon as he leaves, Vitellia is informed by the Praetorian prefect Publio that Tito has, after all, decided to choose her as empress, but it’s too late to stop Sesto.

Sesto wrestles with his conscience as he sets about burning down the Capitol. Everyone believes Tito has died. As they mourn, Vitellia prevents Sesto from confessing.

Act II

Tito has escaped death, and Sesto is caught by Publio, tried by the Senate and, despite Tito’s belief that his friend will be exonerated, convicted. Tito wants to question his erstwhile friend himself before signing the death decree. Sesto confesses but refuses to explain and won’t disclose Vitellia’s role in instigating the plot.

Tito signs the decree, but tears it up. Vitellia, seemingly left with the choice of the throne or saving Sesto’s life, confesses her crime just before Sesto is apparently to be thrown to beasts in the Colosseum. Tito, who had intended to pardon Sesto anyway, extends his clemency to Vitellia and is acclaimed by the Roman public.