Caritea, regina di Spagna

[1] Don Alfonso, the king of Portugal, has declared war on Spain; because the Spanish queen Caritea has refused his offer of marriage, he has decided to take the country by force.

Diego, a Spaniard who is in love with Caritea, arrives at the Portuguese camp, where he asks for entry.

Caritea, who had been in love with Pompey, promised to marry anyone who would deliver her Diego's head.

Caritea, however, reminds him that she has decreed only to marry the man who brings her the head of Don Diego.

Because he managed to kill the enemy of Spain, Don Diego can now reveal his true identity to Caritea.