Io and Zeus
A Love Story of Transformation and Exile
The myth of Io is one of the most dramatic examples of how Zeus's affairs brought suffering not to Zeus himself, but to the women he pursued and the children they bore.
Io was a priestess of Hera at Argos. Zeus desired her and seduced her (or, in some versions, assaulted her). When Hera grew suspicious, Zeus transformed Io into a beautiful white cow to hide her identity. But Hera was not fooled — she demanded the cow as a gift and set the hundred-eyed giant Argus Panoptes to guard her. Zeus sent Hermes to kill Argus, which he did by lulling all hundred eyes to sleep with music and stories before cutting off his head. Hera then placed Argus's eyes on the tail of the peacock, her sacred bird, as a memorial. But Io's suffering was far from over. Hera sent a gadfly to torment Io endlessly, driving her mad as she wandered the earth in cow form. She crossed the strait that was named after her — the Bosporus, meaning 'cow crossing' — and eventually reached Egypt, where Zeus restored her human form. There she bore Zeus's son Epaphus, who became an ancestor of many important mythological figures, including the hero Perseus and the royal house of Argos.
Who Turned Io Into a Cow?
The sources disagree on the most basic point. Apollodorus (Library 2.1.3) gives several possible fathers for Io: most say the river-god Inachus, first king of Argos, while others say Iasus or Peiren. In his account Zeus himself turns Io into a white cow when Hera catches them, and then swears he never touched her. Apollodorus adds, following Hesiod, that this is why lovers' oaths do not draw the anger of the gods. Others say Hera made the transformation. Ovid (Metamorphoses 1.588–600) has Zeus cover the land in cloud to hide the seduction. Hera, seeing a sudden fog on a clear day, comes down to investigate, and Zeus changes Io just in time.
Ovid also adds the most poignant scene. Unable to speak, Io finds her father Inachus and writes her name in the dust with her hoof, two letters, I and O. He realises the heifer is his lost daughter (Metamorphoses 1.649–650).
The Death of Argus
The killing of Argus gave Hermes his old epithet Argeiphontes, usually understood as "slayer of Argus." Versions differ on how he did it. Apollodorus says Hermes killed him with a thrown stone, because he could not approach unseen. Ovid makes it a story within a story: Hermes, disguised as a shepherd, plays the panpipes and begins the tale of Pan and the nymph Syrinx. Before he finishes, all hundred eyes close, and he cuts off the giant's head with a curved sword. Hera then sets the eyes in the peacock's tail (Metamorphoses 1.668–723). Greek vase painters liked the scene. Red-figure pots show Argus covered in eyes, Hermes attacking, and Io as a cow, or sometimes as a woman with small horns.
Io and Prometheus
The fullest classical Greek treatment is in the tragedy Prometheus Bound, traditionally attributed to Aeschylus, where Io appears on stage as a horned maiden still stung by the gadfly. She meets Prometheus chained on his crag in Scythia. He maps out her future wanderings past the Amazons, the Graeae and the Gorgons, across the Bosporus, and on to Egypt. He tells her that the Ionian Sea will carry her name. Then he reveals that one of her descendants, thirteen generations later, will free him. That descendant is Heracles. The play links the two great victims of Zeus's power and makes Io's suffering part of a larger plan.
Aeschylus' Suppliants picks up the family line. The fifty daughters of Danaus flee to Argos and claim protection there as descendants of Io. They argue that Argos is their ancestral home.
Egypt, Isis and a Family of Kings
Greek writers identified Io with Egyptian goddesses. Herodotus (2.41) notes that statues of Isis were horned like the Greek Io. Apollodorus says Io set up a statue of Demeter in Egypt, which the Egyptians called Isis, and that Epaphus was born by the Nile. Herodotus also identified Epaphus with the sacred bull Apis. Epaphus's daughter Libya gave her name to North Africa. Her sons Agenor and Belus founded the royal houses of Phoenicia and Egypt. From that family came Cadmus of Thebes, Europa (another of the lovers of Zeus), Danaus, and eventually Perseus and Heracles.
Herodotus opens his Histories (1.1) with a cynical, rationalised Io. Persian scholars, he says, claim that Phoenician traders kidnapped her from Argos, the first in a chain of abductions between East and West that ended in the Persian Wars. In the Renaissance, Correggio painted Jupiter and Io (c. 1532, Kunsthistorisches Museum, Vienna), in which Zeus is a dark cloud embracing her. The scene was one of a series of loves of Jupiter painted for Federico Gonzaga of Mantua.
Ancient sources
- Aeschylus (attrib.), Prometheus Bound — Io's meeting with Prometheus and his prophecy of her wanderings and descendants.
- Aeschylus, Suppliants — the Danaids trace their claim on Argos back to Io and Epaphus.
- Apollodorus, Library 2.1.3 — variant parentage, Zeus's false oath, Argus killed with a stone, and the birth of Epaphus in Egypt.
- Ovid, Metamorphoses 1.568–747 — the cloud, the name written in the dust, the Syrinx story and the peacock.
- Herodotus, Histories 1.1 and 2.41 — the Phoenician kidnapping version and the comparison of Io with Isis.
- Bacchylides, Ode 19 — a short lyric poem on Io, Argus and Epaphus.
Frequently asked questions
Why is the Bosporus named after Io?
"Bosporus" was explained as "cow's ford", from bous (cow) and poros (passage), because Io crossed it in cow form. Prometheus Bound makes this link.
Who was Io's son?
Epaphus, born in Egypt after Zeus restored her with a touch. His name was linked with the Greek word for "touch". He became a king of Egypt and an ancestor of Perseus and Heracles.
Is Io the same as Isis?
Greek writers identified the two, and Apollodorus says the Egyptians called Io's statue Isis. They were originally separate goddesses, linked by Greek interpretation.