Io.
    Daughter of Inachus, the mythical first king of Argos, Io was a priestess of Hera (Juno). She was seduced by Zeus (Jupiter), who changed her into a beautiful white heifer at the approach of his wife. Hera, suspicious, asked for the heifer as a gift and Zeus was forced to oblige. (In some accounts, Hera herself changed Io into a heifer.) Hera then ordered the many-eyed herdsman, Argus, to watch the animal. He guarded her day and night, closing only two of his eyes at a time to rest. At length, Hermes (Mercury) was summoned by Zeus to kill Argus; he lulled the herdsman to sleep with music — in Ovid's witty adaptation, Mercury bores Argus with the story of Syrinx — and then beheaded him. Hera retrieved the eyes of Argus and placed them on the tailfeathers of her sacred bird, the peacock. Io was haunted by Argus' spirit and plagued to madness with a gadfly sent by Hera. Still, in animal form, she wandered throughout Europe, swam across the sea (now called Ionian) to Thrace, where she came upon Prometheus chained to his rock. When she reached Egypt, Zeus changed her back to human form and, by the touch of his hand (ἐπαφᾶν), produced their son, Epaphus. According to Apollodorus, Io was later identified by the Egyptians with the goddess Isis (or the cow-shaped goddess Hathor).


See also: Prometheus, Bound.