The Orestia is a trilogy of ancient Greek tragedies written by the playwright Aeschylus. It consists of three plays: Agamemnon, The Libation Bearers, and The Eumenides. The story follows the themes of justice, revenge, and the consequences of crime, focusing on the character Orestes, who avenges his father's murder. The trilogy explores the transition from personal vengeance to a system of organized justice. It highlights the conflict between the old ways of retribution and the new legal order represented by the Furies, who transform into the Eumenides, symbolizing the establishment of a court system in Athens.