Io (moon) In Greek mythology, priestess of Hera and daughter of the river god Inachus and Melia, a priestess of Hera at Argos. Zeus seduced the young virgin Io. Afterward he transformed her into a heifer to protect her from the everjealous Hera. Other accounts say Hera transformed her as a punishment for submitting to Zeus. Hera chose Argus, a being with 100 eyes, to watch over Io. Her father, Inachus, looking for his daughter, discovered the heifer, who wrote out her name with her hoof, but Inachus could not help her. At last, Hermes lulled Argus to sleep with songs and stories, then cut off his head. Not giving up, Hera sent a gadfly to punish Io. Io wandered to Egypt, where she was restored to human shape and bore Epaphus, a son of Zeus. The Ionian Sea, according to some accounts, is named after Io, who swam across it after she was changed into a heifer. Ovid’s Metamorphoses (book 1) tells the myth of Io, and she appears in Aeschylus’s Prometheus Bound. In Roman art she appears on the frescoes of the house of Livia on the Palatine in Rome. Correggio painted Io and Jupiter (Zeus).


Encyclopedia of World Mythology and Legend, Third Edition – Written by Anthony S. Mercatante & James R. Dow
Copyright © 2009 by Anthony S. Mercatante




Io, a priestess of Hera in Argos and daughter of river deity, Inachus, also an acolyte of Hera’s, began hearing voices at night advising her to give herself to Zeus. Although this myth is usually given a romantic twist (cheating spouse, Zeus, is described as enamored of beautiful Io), it may actually be the tale of competing deities. Io told her father and he consulted an oracle, which advised him to turn her out of his house and let her roam freely over Earth.

Zeus transformed her into a pretty cow so that he could take her in the form of a bull. Hera, a cow goddess herself, suspected the transformation and placed Io under lock, key, and watchful eyes of her servant, Argos. (Make that one thousand watchful eyes. Argos never slept, closing only half his eyes at any one time.) Zeus sent Hermes to liberate Io. Hera, in turn, sent a gadfly to sting Io. This was no ordinary gadfly, which would have just left a temporary tender spot. Instead, the sting of this gadfly compelled her to run continuously and aimlessly. In The Land of Remorse, his study of Tarantism, author Ernesto De Martino compares Io’s post-sting behavior to those compelled to dance the tarantella ostensibly because of a spider’s bite.

During her compulsive rambling, Io encountered Prometheus, chained and suffering yet still able to comfort her. He prophesied that her journey would end by the Nile River, where Zeus would touch her hand and she would conceive her son, Epaphos, from that touch. Prometheus’ prophecy was accurate: Zeus transformed her back to human form. Io eventually married a king in Egypt. She bore children to Zeus and her husband and is considered the ancestress of heroes. Her descendents were among the nobility of Greece, Egypt, and Phoenicia and presumably roam the Earth still.

Io was also venerated as a lunar goddess, identified with Egyptian cow goddesses Hathor and Isis. The Greeks identified Epaphos with Egypt’s sacred Apis bull.


Io is depicted as a cow or as a cow-horned woman.




Arachne; Europa; Hathor; Hera; Hermes; Isis; Prometheus; Zeus


Encyclopedia of Spirits: The Ultimate Guide to the Magic of Fairies, Genies, Demons, Ghosts, Gods & Goddesses– Written by Judika Illes Copyright © 2009 by Judika Illes.