Agamemnon was the king of Mycenae and commander of the united Greek forces in the Iliad.
He was the son of Atreus and the brother of Menelaus, whose wife Helen’s abduction or departure with Paris helped trigger the Trojan War. As the most powerful Greek ruler in the traditional story, Agamemnon gathered the Achaean kings and princes for the expedition against Troy and served as their overall commander.
The Iliad begins late in the war, focusing on Agamemnon’s quarrel with Achilles. After refusing to return Chryseis, he causes Apollo to send a plague against the Greek camp. He eventually gives her back but takes Achilles’ captive Briseis as compensation, provoking Achilles’ withdrawal from battle.
Agamemnon should not be confused with Menelaus, who was king of Sparta and Helen’s husband, or Odysseus, who ruled Ithaca and was famous for strategy. Later Greek tragedies give Agamemnon a grim homecoming: Clytemnestra kills him after his return from Troy, setting the stage for the story of Orestes.