What is "tigrane"

Tigrane, o vero L'egual impegno d'amore e di fede ( Tigranes or The Equal Ties of Love and Faith) is an opera seria in three acts by the Italian composer Alessandro Scarlatti with a libretto by Domenico Lalli (loosely based on the Histories of Herodotus). It was first performed at the Teatro San Bartolomeo, Naples on 16 February 1715. It is regarded as one of Scarlatti's finest operas. As well as the serious main plot, there are also comic scenes involving the servants Dorilla and Orcone.