The poet invokes the Muse to sing about the rage of Achilles, the Achaeans’ best warrior, against Agamemnon, leader of the Achaean expedition to Troy.

Chryses, a priest of Apollo, arrives at the Achaean camp with a ransom for his daughter Chryseis, who was captured in a raid and given as a prize to Agamemnon. He refuses to give her up, against the other Achaean leaders’ wishes. Frightened by Agamemnon’s violent threats, Chryses withdraws but calls on Apollo to punish the Achaeans. Apollo agrees, sending a plague that ravages the armies.

After 10 days, Achilles calls an assembly to propose consulting a seer. Under Achilles’s protection, Calchas reveals that Apollo sent the plague to punish the Achaeans for disrespecting Chryses; it will continue until his daughter is returned. Agamemnon becomes angry, claiming to prefer Chryseis to his own wife, but agrees to return her if he is compensated with a replacement prize. Achilles counters that it would be a disgrace to confiscate another warrior’s prize. Agamemnon accuses Achilles of trying to cheat him, and Achilles accuses Agamemnon of hoarding the best prizes for himself while Achilles fights “to exhaustion” on Agamemnon’s behalf (83). He threatens to return home to Phthia with his men, the Myrmidons.