Agamemnon was the king of Mycenae and commander of the Greek, or Achaean, forces in the Iliad. He was the elder brother of Menelaus, whose wife Helen’s departure for Troy helped trigger the Trojan War.
In Homer’s story, the Greek army is not a single centralized kingdom. It is an alliance of kings and princes, each leading forces from his own region. Agamemnon holds the senior command because Mycenae is portrayed as especially powerful and because he has the authority and resources to organize the expedition.
His leadership is controversial. At the beginning of the Iliad, Agamemnon quarrels with Achilles after taking Briseis, Achilles’ war prize. Achilles withdraws from battle, and the Greek army suffers badly until the conflict is eventually repaired. Agamemnon is therefore both the political leader of the army and one of the main causes of its internal crisis.
He should not be confused with Menelaus, king of Sparta and Helen’s husband, or Odysseus, the famous king of Ithaca and strategist. Agamemnon’s later fate is also tragic: myths say he was murdered after returning from Troy.