About the work
Demetrio is a two-act opera seria by Johann Simon Mayr, adapting Pietro Metastasio's 1732 libretto of the same name, earlier set by composers including Johann Adolph Hasse. It was Mayr's final opera, first performed on 27 December 1823 at the Teatro Regio in Turin.
Plot
The plot follows the deposed Syrian king Demetrio Soter. His son grows up in hiding under the assumed name Alceste, admired for his virtue, and falls in love with Cleonice, daughter of the usurper Alexander Balla. Only after Balla's defeat by the Cretans is Alceste's true royal lineage revealed.
Cultural significance
Mayr deliberately returned to the conventions of opera seria, trading the idiosyncratic instrumentation of his earlier works for a more monumental orchestral sound. Written during a period of political censorship after the Congress of Vienna, the story of a rightful ruler's return could also be read as a message in favour of the restored conservative order.