In Greek mythology the Erinyes (Ερινύες) or Eumenides (or Furies in Roman mythology) were female personifications of vengeance. A formulaic oath in the Iliad (iii.278ff; xix.260ff) invokes them as "those who beneath the earth punish whoever has sworn a false oath." Burkert suggests they are "an embodiment of the act of self-cursing contained in the oath" (Burkert 1985 p 198). They were usually said to have been born from the blood of Ouranos when Cronus castrated him. According to a variant account, they issued 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 ("unceasing," who appeared in Virgil's Aeneid), Megaera ("grudging"), and Tisiphone ("avenging murder"). Dante followed Virgil in depicting the same three-charactered triptych of Erinyes. The heads of the Erinyes were wreathed with serpents (compare Gorgon), their eyes dripped with blood, and their whole appearance was horrific and appalling. Sometimes they had the wings of a bat or bird, or the body of a dog.

The Erinyes often stood for the rightness of things within the standard order; for example, Heraclitus declared that if Helios decided to change the course of the Sun through the sky, they would prevent him from doing so. However, they were predominantly understood as the persecutors of mortal men and women who broke "natural" laws. In particular, those who broke ties of kinship through murdering a father (patricide), murdering a brother (fratricide), or other such familial killings brought special attention from the Erinyes. It was believed in early epochs that human beings might not have the right to punish such crimes, instead leaving the matter to the dead man's Erinyes to exact retribution.

The Erinyes were connected with Nemesis as enforcers of a just balance in human affairs. The goddess Nike originally held a similar role as the bringer of a just victory. When not stalking victims on Earth, the Furies were thought to dwell in Tartarus where they applied their tortures to the damned souls there.

The Erinyes are particularly known for the persecution of Orestes for the murder of his mother, Clytemnestra. Since Apollo had told Orestes to kill the murderer of his father, Agamemnon, and that person turned out to be his mother, Orestes prayed to him. Athena intervened and the Erinyes turned into the Eumenides ("kindly ones"), as they were called in instances portraying their more positive, beneficial qualities.

Nonetheless, many scholars believe that when they were originally referred to as the Eumenides, it was not to reference their good sides but as a euphemism to avoid the wrath that would ensue from calling them by their true name. The taboo in speaking the names of certain uncanny spirits included Persephone, and there are parallels in many cultures (for instance, the tendency to refer to faeries as "the fair folk" or "the little people"). The Erinyes might also be recognized as Semnai ("the venerable ones"), the Potniae ("the Awful Ones"), the Maniae ("the Madnesses") the Praxidikae ("the Just-doers") and Kampesigounoi ("bending the knees").

Another myth says that the Erinyes struck the magical horse Xanthus dumb for rebuking Achilles.

The Furies (their Roman name) or Dirae ("the terrible") typically had the effect of driving their victims insane, hence their Latin name furor.

The Erinyes are the main subject of the comic book The Kindly Ones from comic book series Sandman.

• Nemesis (mythology)
• Karma
• Lilith

• Iliad xiv.274-9; xix.259f.
• Virgil, Aeneid vii, 324, 341, 415, 476.
• Burkert, Walter, 1977 (tr. 1985). Greek Religion (Harvard University Press).