Attilio Regolo is an Italian-language opera seria by Johann Adolph Hasse based on the story of Marcus Atilius Regulus, a Roman general taken prisoner in Carthage who elects death rather than ransom. Pietro Metastasio wrote the libretto in 1740 for the birthday of the emperor Charles VI and supplied exacting notes to Hasse for its setting in music, despite the composer's having set several Metastasio librettos before. Hasse completed the score within three months,[1] but the emperor's illness, then death, prevented the opera from being performed. It was not until 12 January 1750 that the premiere took place, at the Opernhaus am Zwinger in Dresden.[2] The role of Regolo was taken by the castrato Domenico Annibali, while the role of Attilia was composed for Hasse's wife Faustina Bordoni.