Who was the Greek king who argued with Achilles over Briseis?

Agamemnon was the Greek king who argued with Achilles over Briseis in the Iliad. He was king of Mycenae and commander-in-chief of the Greek, or Achaean, forces besieging Troy. Although Achilles was the army's greatest fighter, Agamemnon held supreme political authority, making their confrontation a clash between military excellence and royal power.

The dispute begins after Agamemnon returns Chryseis to her father to end Apollo's plague on the Greek camp. Angry at losing his own captive, he claims Briseis, Achilles' allotted war prize, as compensation. Achilles sees this as a humiliating violation of his status and refuses to fight.

Agamemnon later sends gifts and an embassy to persuade Achilles to return, but Achilles rejects the offer. He comes back only after Patroclus is killed by Hector. In Book 19, Agamemnon and Achilles are reconciled, and Briseis is returned. The quarrel is not a minor disagreement: Achilles' anger and withdrawal form the central subject of the epic.