Synopsis

Act I

King Mitridate of Pontus has been defeated by the Romans and is widely believed to have died in battle. Before leaving for war, he placed his fiancée, Aspasia, under the protection of his two sons, Sifare and Farnace. The brothers, however, have very different loyalties: Sifare remains faithful to his father, while Farnace has secretly allied himself with Rome. The two sons, with Aspasia, have fled to the province of Ninfea to consult with Mitirdate’s trusted advisor Arbate.

Both sons have fallen in love with Aspasia. Farnace openly pursues her and hopes to claim both her and the throne for himself, but Aspasia rejects his advances and seeks protection from Sifare. Although Sifare secretly loves her as well, he refuses to betray his father. As their mutual affection begins to emerge, they struggle to keep their feelings hidden.

The situation changes dramatically when Mitridate unexpectedly returns alive. He reveals that he has survived the war and arrives with Ismene, a princess who intends to marry Farnace. Mitridate orders the marriage to proceed, but Ismene quickly realizes that Farnace no longer loves her. Soon, Mitridate learns that Farnace has been courting Aspasia and conspiring with the Romans. Convinced of his son’s treachery, the king begins plotting punishment.

Act II

Ismene confronts Farnace about his unfaithfulness, but he coldly rejects her. Although she seeks help from Mitridate, she still hopes Farnace can be redeemed. Mitridate, meanwhile, announces that he will marry Aspasia without delay. When she fails to show enthusiasm, he suspects that she loves one of his sons.

Aspasia and Sifare confess their feelings for one another, but both agree that they must sacrifice their happiness rather than dishonor Mitridate.

INTERMISSION

Mitridate unveils his battle plan to defeat Rome. Farnace, arguing for a peace treaty with Rome, is accused of treason by his father. Before being thrown in prison, Farnace reveals Sifare’s love for Aspasia in an effort to bring his brother down with him.

Mitridate tricks Aspasia into revealing her feelings for Sifare. Feeling betrayed by his fiancée and both sons, Mitridate explodes in rage and condemns Sifare and Aspasia to death.

Act III

As the Romans renew their assault, Mitridate prepares for battle while still consumed by anger. Ismene pleads for mercy, and Aspasia offers to accept any punishment if Sifare can be spared. Mitridate refuses and orders their execution before leaving for the battlefield.

Aspasia receives poison as a final gift from the king and prepares to die. At the last moment, Sifare rushes in and saves her. He then goes to fight beside his father, hoping to prove his loyalty. Farnace is released by the Roman envoy who offers him the crown, but he finally recognizes the depth of his betrayal. Rejecting both Rome and his ambitions, Farnace turns against his former allies and helps destroy the Roman fleet.

The battle ends with Mitridate mortally wounded after choosing death over capture. As he dies, he acknowledges Sifare’s devotion and blesses the union of Sifare and Aspasia. Learning that Farnace has redeemed himself by fighting for Pontus, he forgives his elder son as well. After Mitridate’s death, the survivors vow to wage everlasting war against the Roman Empire.