For those familiar with the stories surrounding the Trojan War, you might remember that one of the Greek heroes was Agamemnon. The first play of the Oresteia — a trilogy written by Aeschylus — tells of his return from war and his murder at the hands of his wife, Clytemnestra. Her reasons for doing so are debatable, but include the fact that when Agamemnon departed for Troy, he sacrificed his and Clytemnestra’s daughter, Iphigenia, for a fair wind, and the fact that Agamemnon returned from Troy with the daughter of the former ruler of Troy, a seer named Cassandra, for a concubine (whom Clytemnestra also killed). And there’s also the fact that Clytemnestra had started up an adulterous affair with Aegisthus, Agamemnon’s cousin from a rather unfasionable side of the family, determined to take his place as ruler (which was conveniently accomplished by the death of Agamemnon). Welcome to the House of Atreus.
The second play, The Libation Bearers, tells of the reunion of Agamemnon’s children. Agamemnon’s son, Orestes, and his friend Pylades, return to the old family home. (Orestes has been raised in exile in Phocis, Pylades’ home, since things weren’t so great at his own place). He ran across his long-lost sister, Electra, with a group of women pouring funeral libations onto Agamemnon’s grave. Apparently, Clytemnestra had a bad nightmare involving giving birth to a snake and took it for a bad omen. Feeling guilty, she ordered the libations to Agamemnon’s grave in order to ward off the bad juju. Orestes and Electra have a spout of “Daddy was so much better than Mommy” and decide that Mommy and Step-Dad need to die. Orestes and Pylades disguise themselves and kill both Aegisthus and Clytemnestra.
The third play, The Eumenides or The Furies, is essentially a trial with Orestes as the defendant and the ghost of Clytemnestra as the plaintiff. The Furies have been tormenting Orestes since their raison d’être is to avenge patricide and matricide, and Orestes would rather like them to stop torturing him. They go to Athens where Athena appoints eleven Athenians to sit in judgement with her as they listen to each side. The Furies play prosecution for Clytemnestra’s behalf while Apollo acts as defense attorney for Orestes. In the end, Apollo points out that Athena herself was born from Zeus alone without a mother, therefore the father and the man in a marriage is more important, therefore Orestes was right in killing his mother to avenge her murder of his father. Athena renames the Furies to The Eumenides (meaning the kindly ones) and bids Athenians to worship them. She also takes the opportunity to set up all modern law, including the practice of a 12 person jury that she has just now invented, and the decision that a hung jury should result in acquittal. The play ends with Clytemnestra and the Eumenides singing cheerily about peace in the afterlife, and all is well.