trilogy of tragic dramas by the ancient Greek dramatist Aeschylus, first performed in 458 BC. It is his last work and the only complete trilogy of Greek dramas that has survived.

The Oresteia tells the story of the house of Atreus. The first play, Agamemnon, portrays the victorious return of that king from the Trojan War and his murder by his wife, Clytemnestra, and her lover, Aegisthus. The second play, Choephoroi (The Libation Bearers), deals with Agamemnon's daughter Electra and his son Orestes. Orestes avenges his father's murder by killing his mother and her lover. The third play, Eumenides, describes Orestes driven by the Furies (Erinyes), for, though he was required to avenge his father's death, a matricide is infamous in the eyes of the gods. He is finally absolved at the court of the Areopagus by the goddess Athena.