About the work
Dramma per musica in three acts by Antonio Caldara to a libretto by Pietro Metastasio, first performed on 4 November 1733 at the Vienna Hoftheater for the nameday of Emperor Charles VI. It was the first setting of a text Metastasio had written specifically for the Viennese court; the ballet music is by Nicola Matteis the Younger.
Plot
An oracle in Thrace demands the yearly sacrifice of a virgin of royal blood. King Demofoonte spares his own daughter, while the powerful nobleman Matusio insists that his supposed daughter Dircea be sacrificed instead — though she is secretly married to Demofoonte's son Timante and already has a child by him. Only when it emerges that Dircea is in fact Demofoonte's true daughter, and Timante Matusio's son, can the secret marriage be acknowledged and the oracle satisfied.
Cultural significance
Metastasio deliberately softened the crueller features of earlier versions of the story, earning praise from contemporaries; the text went on to receive more than seventy settings. Charles VI's Vienna court opera cast the premiere with seven soloists and orchestra, and the score survives today in two manuscripts held by the Austrian National Library.