Aeschylus’ The Oresteia is a trilogy of Greek tragedies concerning the murder of King Agamemnon of Argos, together with its aftermath. The name derives from the character Orestes, the son of Agamemnon, who sets out to avenge his father's murder. The three plays – Agamemnon, Choephori (Libation-Bearers) and Eumenides (The Furies) – were originally accompanied in performance by a satyr play, Proteus, now lost. The Oresteia, which won first prize at the Dionysia festival in 458 BC, is the only surviving example of an ancient Greek theatre trilogy.
This translation by Marianne McDonald and J. Michael Walton is based on the Oxford text (to which the line numbers refer). It follows a distinction in the original text between the lines spoken by the characters (which are mostly composed in iambics), and those spoken by the Chorus (which adopt a much freer lyric verse); here, the lyric passages belonging to the Chorus are identified by the use of initial capital letters for each new line. In addition, various expressions such as io, pheu, oimoi and others have been left transliterated from the original Greek, being (in the words of the translators) 'indications of grief rather than actual words'.
The first play of the trilogy, Agamemnon, details the homecoming of Agamemnon, King of Argos, from the Trojan War. Waiting at home for him is his wife, Clytemnestra, who has been planning his murder, partly as revenge for the sacrifice of their daughter, Iphigenia, and partly because in the ten years of Agamemnon's absence Clytemnestra has entered into an adulterous relationship with Aegisthus, Agamemnon's cousin and the sole survivor of a dispossessed branch of the family (Agamemnon's father, Atreus, killed and fed Aegisthus's brothers to Aegisthus's father, Thyestes, when he took power from him), who is determined to regain the throne he believes should rightfully belong to him.
The second play, Choephori, deals with the reunion of Agamemnon's children, Electra and Orestes, and their revenge. Orestes kills his mother Clytemnestra to avenge the death of his father.
In the final part, Eumenides, Orestes, Apollo, and the Erinyes go before Athena and eleven other judges chosen by her from the Athenian citizenry to decide whether Orestes' killing of Clytemnestra makes him guilty of the crime of murder.