• Wolfgang Amadeus Mozart. Opera seria in two acts. 1791.
• Libretto adapted by Caterino Mazzola from Metastasio.
• First performance at the Prague National Theatre on 6th September 1791.

Vitellia, jealous of Titus, persuades Sextus, who is in love with her, to plot against his friend, the Emperor. Annius seeks from Sextus the hand of his sister, which he grants. Titus, rejecting a foreign marriage, now declares that he will marry Servilia, in order to honour Sextus. She tells Titus that she loves Annius, and he releases her from marriage with him. Vitellia still urges Sextus to assassinate Titus, but when she learns that she is to be the wife of Titus, she becomes anxious to prevent the plot, which is now afoot. Titus survives and Sextus is found guilty, still refusing to implicate Vitellia, who finally admits her guilt, to be forgiven by the magnanimous Emperor.

Mozart's opera was commissioned by Prague for the coronation of Leopold II as King of Bohemia, after no such work had been sought to mark the Emperor's coronation in Vienna. The Empress Maria Luisa notoriously described the work as porcheria tedesca (German piggery), claiming that the music was very bad, and that most of the audience slept through the performance, but the work certainly enjoyed later popularity. It makes use of an old libretto, in a revised version of the opera seria libretto of Metastasio, suggesting new ways in which the older form might now be treated. The overture is familiar in concert repertoire, while Parto, parto (I go, I go) of Sextus, with its basset clarinet obbligato for Anton Stadler, and Vitellia's Non più di fiori (No more with flowers), with the same obbligato instrument, may also be heard in recital as part of present soprano repertoire.