The opera was first performed at the Teatro San Carlo in Naples on 20 January 1775, the birthday of king Charles III of Spain, the former ruler of the Kingdom of Naples whose birthday and nameday were still celebrated with operatic productions under the rule of his son Ferdinand.
It was very successful at its premiere, to the point that the prima donna for the production, Antonia Bernasconi, specially brought arias from it with her to her next engagement in London.
The Thracian king Demofoonte asks the oracle of Apollo how long the practice of the annual sacrifice of a virgin will continue.
The marriage of Timante and Dircea becomes legal, and Cherinto is the real crown prince and can marry Creusa.
Timante" Act II, scene 10 - Duet for Dircea and Timante, "La destra ti chiedo" Act III, scene 1 - Aria of Adrasto, "Se ti bramassi estinto" [a non-Metastasian text] Act III, scene 4 - Accompanied recitative for Timante, "Misero me" Act III, scene 5 - Aria of Timante, "Misero pargoletto" Act III, scene 6 - Aria of Demofoonte, "Odo il suono de' queruli accenti" Act III, scene 7 - Aria of Dircea, "Che mai risponderti" The complete score of Mysliveček's Demofoonte of 1775 is available for study online on the Italian website Internet Culturale in the form of a reproduction of a manuscript once in the possession of the Teatro San Carlo of Naples.