The poet invokes a muse to aid him in telling the story of the rage of Achilles, the greatest Greek hero to fight in the Trojan War. The narrative begins nine years after the start of the war, as the Achaeans sack a Trojan-allied town and capture two beautiful maidens, Chryseis and Briseis. Agamemnon, commander-in-chief of the Achaean army, takes Chryseis as his prize. Achilles, one of the Achaeans’ most valuable warriors, claims Briseis. Chryseis’s father, a man named Chryses who serves as a priest of the god Apollo, begs Agamemnon to return his daughter and offers to pay an enormous ransom. When Agamemnon refuses, Chryses prays to Apollo for help.

Apollo sends a plague upon the Greek camp, causing the death of many soldiers. After ten days of suffering, Achilles calls an assembly of the Achaean army and asks for a soothsayer to reveal the cause of the plague. Calchas, a powerful seer, stands up and offers his services. Though he fears retribution from Agamemnon, Calchas reveals the plague as a vengeful and strategic move by Chryses and Apollo. Agamemnon flies into a rage and says that he will return Chryseis only if Achilles gives him Briseis as compensation.

Agamemnon’s demand humiliates and infuriates the proud Achilles. The men argue, and Achilles threatens to withdraw from battle and take his people, the Myrmidons, back home to Phthia. Agamemnon threatens to go to Achilles’ tent in the army’s camp and take Briseis himself. Achilles stands poised to draw his sword and kill the Achaean commander when the goddess Athena, sent by Hera, the queen of the gods, appears to him and checks his anger. Athena’s guidance, along with a speech by the wise advisor Nestor, finally succeeds in preventing the duel.

That night, Agamemnon puts Chryseis on a ship back to her father and sends heralds to have Briseis escorted from Achilles’ tent. Achilles prays to his mother,