Agamemnon
King of Mycenae and Argos, was brother to Menelaus, and son of Plisthenes, the son of Atreus. He married Clytemnestra, and Menelaus married Helen; both were daughters of Tyndarus, king of Sparta.
When Helen eloped with Paris, Agamemnon was elected commander-in-chief of the Grecian forces invading Troy.