Handel's opera Rinaldo is set in Crusader times. Goffredo and his army are laying siege to Jerusalem. With Goffredo are his daughter Almirena, and the knight Rinaldo, who declares his love for Almirena. Goffredo promises Almirena will be Rinaldo's bride when Jerusalem falls. She urges Rinaldo to fight boldly and assure victory.
Goffredo accepts a three-day truce requested by the Saracen general, Argante. His lover, the sorceress and Saracen Queen, Armida, appears and kidnaps Almirena, despite Rinaldo’s attempts to defend her.
Almirena, held captive by Armida, laments her cruel fate. In a series of Baroque twists, Rinaldo – seeking to release Almirena – is lured away, then captured and Armida falls in love with him, while Argante has fallen for Almirena. The lovers remain true to each other; Armida is outraged by Argante’s infidelity and vows vengeance.
With the aid of a magician, Goffredo frees his daughter and Rinaldo and they celebrate their reunion. They must, however, face a battle with Argante and Armida, now reconciled. The Crusaders, led by Rinaldo, are victorious. Rinaldo and Almirena celebrate their love, while Armida and Argante accept their defeat. Goffredo forgives his enemies and sets them free. The opera concludes in a chorus of reconciliation.