About the work
Demetrio is an opera seria in three acts by Josef Mysliveček, setting Pietro Metastasio's libretto that had premiered at the Viennese court in 1731 and tells of the Seleucid king Demetrius II Nicator. Mysliveček wrote his version for Naples, where it premiered at the Teatro San Carlo on 13 August 1779 to mark Queen Maria Carolina's birthday.
Plot
A king's son raised as a shepherd under the name Alceste is revealed at the right moment by his guardian Fenicio to be the rightful heir to the Syrian throne. Having proven himself worthy, he marries Queen Cleonice and ascends the throne.
Cultural significance
It was the ninth and final opera Mysliveček wrote for the Teatro San Carlo between 1767 and 1779 — more commissions from that house than any other composer received in the period. The run of performances was interrupted by an eruption of Vesuvius, and the opera's success was only modest.