"Agamemnon" is the first of the three linked tragedies which make up "The Oresteia" trilogy by the ancient Greek playwright Aeschylus. Trilogy as a whole, originally performed at the annual Dionysia festival in Athens in 458 BCE, where it won first prize, is considered to be Aeschylus' last authenticated, and also his greatest, work.
"Agamemnon" describes the homecoming of Agamemnon, king of Argos, from the Trojan War, and his return to his wife, Clytemnestra, who had been planning his murder (in concert with her lover, Aegisthus) as revenge for Agamemnon's earlier sacrifice of their daughter, Iphigenia.
