In Greek mythology the Erinyes (Ἐρινύες, pl. of Ἐρινύς, Erinys; literally "the avengers") from Greek ἐρίνειν " pursue, persecute"--sometimes referred to as "infernal goddesses" (Greek χθόνιαι θεαί)-- were female chthonic deities of vengeance. A formulaic oath in the Iliad invokes them as "those who beneath the earth punish whosoever has sworn a false oath".^[1] Burkert suggests they are "an embodiment of the act of self-cursing contained in the oath".^[2]

They correspond to the Furies or Dirae in Roman mythology. Furies are the warriars of the underworld

When the Titan Cronus castrated his father Uranus and threw his genitalia into the sea, the Erinyes emerged from the drops of blood, while Aphrodite was born from the crests of seafoam. According to variant accounts,^{[3][4][5] [6]} they emerged from an even more primordial level—from Nyx, "Night". Their number is usually left indeterminate. Virgil, probably working from an Alexandrian source, recognized three: Alecto ("unnameable" who appeared in Virgil's Aeneid), Megaera ("grudging"), and Tisiphone ("vengeful destruction"). Dante followed Virgil in depicting the same three-charactered triptych of Erinyes; in Canto IX of the Inferno they confront the poets at the gates of the city of Dis. The heads of the Erinyes were wreathed with serpents (compare Gorgon) and their eyes dripped with blood, rendering their appearance rather horrific. Other depictions show them with the wings of a bat or bird and the body of a dog.

In Aeschylus's "Eumenides", the story begins with Agamemnon's return home, to find that his wife, Clytemnestra, had married her lover, Aegisthus. Cassandra, daughter of Priam (who was awarded to Agememnon as part of the spoils of war) used her prophetic powers to see that Clymenestra and her lover plotted Agememnon's death. However Agememnon did not believe this, and while leaving the bath one day, was caught in a net planted by his wife and then slain by her lover. Their son, Orestes saw, and fled. When Orestes reached manhood, he was commanded by one of Apollo’s oracles to avenge his father‘s murder at his mother’s hand. Orestes hastened to follow Apollo’s orders. He returned home and revealed himself to his sister. However, to his mother, he pretended to be a messenger bringing her the news of her son’s death. Rather than showing remorse, as any normal mother would, Clytemnestra was overcome with joy. When Orestes saw this he realized that his mother suffered no remorse for her actions and slew Clytemnestra, while his friend Pylades slew her lover. Agamemnon was avenged. Although Orestes’ actions were what the god Apollo had commanded him to do, Orestes had still committed matricide and because of this, he was handed over to the terrible Erinyes. They pursued him relentlessly and upon reaching Delphi he was told by Apollo that he should bring from Taurus the statue of the goddess Artemis. The people of Taurus were known for habitually offering those who came to their shore as sacrifices. However, the priestess of Taurus was actually Orestes’ sister Iphigenia, who had been taken by Artemis to be her priestess when Agamemnon offered her as a sacrifice. With his sister’s help, Orestes managed to bring the statue back to Greece. The Furies, however were still not satisfied with this, so with Apollo’s guidance Orestes went to Athens and asked for a trial in the Areopagus (Judges in a court specifically appointed for murder. The Furies appeared as Orestes’ accusers, while Apollo spoke in defence. When the votes were cast there was an even amount for acquittal, and for condemnation. Athena was asked to vote, and she did so in Orestes’ favour. He was acquitted. After this process the Furies were satisfied and at this point the names changed to Eumenides, meaning ‘the kindly ones’. Orestes assumed the throne and married Hermione, daughter of Menelaus and Helen.

In Euripides Orestes (play) they are for the first time "equated"^[7] with the Eumenides (Εὐμενίδες, pl. of Εὐμενίς; literally "the gracious ones" but also translated as "Kindly Ones"^[8][9])

• Aeschylus, "Oresteia" Trans. Lloyd-Jones. Lines 788–1047.
• Homer, Iliad xiv.274–9; xix.259f.
• Virgil, Aeneid vii, 324, 341, 415, 476.
• Burkert, Walter, 1977 (tr. 1985). Greek Religion (Harvard University Press).
• Scull, S A. Greek Mythology Systematized. Philadelphia: Porter & Coates, 1880. Print.
• Wilk, Stephen R. Medusa: Solving the Mystery of the Gorgon. Oxford: Oxford University Press, 2000. Google Book Search. Web. 24th October, 2011.
• Littleton, Scott. Gods, Goddesses, and Mythology, Volume 4. Marshall Cavendish Corporation, 2005. Google Book Search. Web. 24th October, 2011.