Axur, King of the Persian Gulf kingdom of Ormus, orders one of his soldiers, Altamor, to abduct Aspasia, the wife of Atar, the heroic commander of Axur's army. Not knowing who kidnapped Aspasia but suspecting an overseas enemy, Atar speaks with the king and begs for justice. Moved by his appeal, Axur allows Atar to take a ship and seek his wife. Before Atar leaves, Axur's slave-servant, Biscroma, tells the general that the king has abducted Aspasia and hidden her in the royal harem. Enemy troops now threaten to invade Ormus, and the people plead with Atar to save them. Axur undermines Atar by telling the people that the general has better things to do than lead the army. Enraged, Atar declares himself ready to stand at the head of the army and wipe out the nation's enemies.