Io (mythology) 

Hermes, Io (as cow) and Argus, black-figure amphora, 540–530 BC, Staatliche Antikensammlungen (Inv. 585)

In Greek mythology, Io (pronounced /ˈaɪoʊ/ or /ˈiːoʊ/, World Book «EYE oh», in Ancient Greek Ἰώ [iː.ɔɔ̗]) was a priestess of Hera in Argos1 who was seduced by Zeus, who changed her into a heifer to escape detection. Her mistress Hera set ever-watchful Argus Panoptes to guard her, but Hermes was sent to distract the guardian and slay him. Heifer Io was loosed to roam the world, stung by a maddening gadfly sent by Hera, and wandered to Egypt, thus placing her descendant Belus in Egypt; his sons Cadmus and Danaus would thus "return" to mainland Greece.

Zeus makes love with Io, painting by Antonio da Correggio c. 1531

Io's father is generally given as Inachus, a river god credited with inaugurating the worship of Hera in the region of Argos, thus establishing her as an autochthonous spirit of the Argolid2 and as by her nature a nymph of a spring, a naiad.3

The myth is told most anecdotally by Ovid, in Metamorphoses. According to Ovid, one day, Zeus noticed the maiden and lusted after her. As Io tells her own story in Aeschylus' Prometheus Bound, she rejected his whispered nighttime advances until the oracles caused her own father to drive her out into the fields of Lerna. There, Zeus covered her with clouds to hide her from the eyes of his jealous wife, Hera, who nonetheless came to investigate. In a vain attempt to hide his crimes, Zeus turned himself into a white cloud and transformed Io into a beautiful white heifer. Hera was not fooled. She demanded the heifer as a present.

Hera tethered Io to the olive-tree in the temenos of her cult-site, the Heraion, and placed her in the charge of many-eyed Argus Panoptes to keep her separated from Zeus. Zeus commanded Hermes to kill Argus; Ovid added the detail that he lulled all hundred eyes to sleep. Hera then forced Io to wander the earth without rest, plagued by a gadfly (Οίστρος or oestrus: see etymology of "estrus" ) to sting her into madness. Io eventually crossed the path between the Propontis and the Black Sea, which thus acquired the name Bosporus (meaning ox passage), where she met Prometheus.

Prometheus had been chained on Mt. Caucasus by Zeus for teaching Man how to make fire and tricking him into accepting the worse part of a sacrifice while the mortals kept the better part (meat); every day, a giant eagle fed on Prometheus' liver. Despite his agony, he comforted Io with the information that she would be restored to human form and become the ancestress of the greatest of all heroes, Heracles. Io escaped across the Ionian Sea to Egypt, where she was restored to human form by Zeus. There, she gave birth to Zeus's son Epaphus, and a daughter as well, Keroessa. She later married Egyptian king Telegonus. Their grandson, Danaos, eventually returned to Greece with his fifty daughters (the Danaids), as recalled in Aeschylus' play The Suppliants.

The myth of Io must have been well-known to Homer, who often calls Hermes Hermes Argeiphontes, "Hermes Argus-slayer." Walter Burkert4 notes that the story of Io was told in the ancient epic tradition at least four times of which we have traces: in the Danais, in the PhoronisPhoroneus founded the cult of Hera, according to Hyginus' Fabulae 274 and 143— in a fragment of the Hesiodic Aigimios as well as in an Oxyrhynchus papyrus fragment supplementing the Hesiodic Catalogue of Women. A mourning commemoration of Io was observed at the Heraion of Argos into classical times.

The mythic events concerning Io were transplanted, no doubt by colonists from Argos, to various far-flung sites in the Hellenic world.

The ancients connected Io with the Moon,5 and in Aeschylus' Prometheus Bound, where Io encounters Prometheus, she refers to herself as "the horned virgin", both bovine and lunar.

Notes

  1. ^ In a fragment of the Hesiodic Catalogue of Women.
  2. ^ A genealogy constructed for a "House of Argos" cannot be reconciled with the myths.
  3. ^ Other fathers, Iasos or Peiren are briefly noted in Bibliotheke 2.5
  4. ^ Burkert, Homo Necans (1974) 1983:164 note 14, giving bibliography.
  5. ^ Eustathius of Thessalonica commentary on Dionysius Periegetes, 92; the Byzantine encyclopedia Suda s.v. "Io", Hesychius, s.v. "Io".

External links

Argive genealogy in Greek mythology
 
 
 
 
 
 
 
 
 
 
Uranus
 
Gaia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Cronus
 
Rhea
 
Oceanus
 
Tethys
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Memphis
 
 
Libya
 
Poseidon
 
 
 
Nilus
 
Inachus
 
Melia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Belus
 
Agenor
 
 
 
Telephassa
 
 
Phoroneus
 
Io
 
Zeus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Cadmus
 
Cilix
 
Europa
 
Phoenix
 
Achiroe
 
 
 
Epaphus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Harmonia
 
 
Danaus
 
Aegyptus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Polydorus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Agave
 
 
Hypermnestra
 
Lynceus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Autonoë
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Ino
 
 
 
 
Abas
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Semele
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Proetus