Io

Io was a princess of Argos, a priestess of Hera, and a lover of Zeus. Hera turned her, or Zeus turned her to hide her from Hera, into a white cow, and then set the hundred-eyed Argus to guard her. Driven by a gadfly across Europe and Asia, Io reached Egypt, where she regained her human shape and bore Epaphus. Her descendants include Danaus, Cadmus and Heracles.

Parentage and Family

Most writers make Io the daughter of the river-god Inachus of Argos: Aeschylus (Prometheus Bound 589–590, 663), Ovid (Metamorphoses 1.611, 651–653) and Herodotus, who calls her “the daughter of Inachus” in both the Persian and the Greek telling (Histories 1.1). Apollodorus records the other versions: according to some she was the daughter of Iasus, son of Argus and Ismene, and Hesiod and Acusilaus said she was the daughter of Piren (Apollodorus, Library 2.1.3). Her son by Zeus was Epaphus. Epaphus’s own line is traced in the Library: his daughter Libya bore Agenor and Belus to Poseidon, and Belus was the father of Egyptus and Danaus (Library 2.1.4), while Agenor was the father of Europa and Cadmus (Library 3.1.1).

Zeus and Io

In Apollodorus, Zeus seduced Io while she held the priesthood of Hera (Library 2.1.3). In Aeschylus Io tells her own story: night visions urged her to leave her father’s house for the meadows of Lerna, where Zeus desired her. Her father Inachus sent to Pytho and Dodona for guidance and finally received a clear oracle. He had to drive her from his house and land, to wander at the ends of the earth, or Zeus’s thunderbolt would destroy his whole family, and so he drove her out (Prometheus Bound 640–672). At once her shape and mind were changed, and she rushed away horned and stung by the gadfly (Prometheus Bound 673–676).

The Cow and Argus

In Ovid, Zeus covered the land in dark clouds to hide his meeting with Io. Hera noticed the darkness in daylight, came down and drove the mist away; Zeus had already turned Io into a bright heifer (Metamorphoses 1.599–611). When Hera asked whose cow it was and where it came from, he lied that it had been born from the earth. She asked for it as a gift, and he had no safe way to refuse (Metamorphoses 1.612–617). Apollodorus adds that Zeus swore he had not lain with her, and he quotes Hesiod that the gods do not punish lovers’ oaths. He says Zeus changed her into the cow by a touch (Library 2.1.3).

Hera gave the cow to Argus to guard. Ovid describes him as the son of Arestor, with a hundred eyes, only two of which slept at a time (Metamorphoses 1.624–626). Apollodorus records different parentages for Argus: Pherecydes made him a son of Arestor, Asclepiades a son of Inachus, Cercops a son of Argus and Ismene, and Acusilaus said he was earth-born; he tethered Io to an olive tree in the grove of the Mycenaeans (Library 2.1.3). Ovid shows Io pastured by day and chained at night, able to complain only by lowing (Metamorphoses 1.630–638). In one scene she meets her father and her sisters, the Naiads, on the banks of the Inachus and writes her name with her hoof in the dust, so that Inachus recognizes his daughter (Metamorphoses 1.635–667).

The Death of Argus

Zeus sent Hermes to free her. In Ovid, Hermes came disguised as a goatherd playing on pipes, sat with Argus and told him stories until all his eyes slept, then struck off his head with a curved sword (Metamorphoses 1.668–721). Apollodorus gives a shorter version in which Hermes, unable to steal the cow secretly, killed Argus with a thrown stone, and this is why he was called Argiphontes, “slayer of Argus” (Library 2.1.3). Hera took Argus’s eyes and set them in the tail of her bird, the peacock (Ovid, Metamorphoses 1.722–723).

Io’s Wanderings

Hera then sent a gadfly against the cow (Apollodorus, Library 2.1.3); Ovid has her send a Fury instead (Metamorphoses 1.724–727). In Aeschylus, Io is also pursued by the phantom of Argus (Prometheus Bound 567–568). Apollodorus traces her route: first to the gulf called Ionian after her, then through Illyria, over Mount Haemus, and across the Thracian strait, now called the Bosporus, “cow’s ford”, then to Scythia and the Cimmerian land, and finally across great stretches of Europe and Asia to Egypt (Library 2.1.3).

In Aeschylus, Io meets the chained Prometheus in a desolate land of Scythia at the edge of the world (Prometheus Bound 1–2). He foretells that she will go east, past the Scythians and the Chalybes, over the Caucasus, and cross the strait that will be named Bosporus for her, until she reaches the Nile. There Zeus will give her back her mind by a touch of his hand, and she will bear a dark son, Epaphus. Five generations later the fifty daughters of Danaus will come back to Argos, and one of them, who spares her husband, will bear a line of kings. From that line will come an archer who will free Prometheus (Prometheus Bound 700–735, 788–876). Apollodorus names this hero as Heracles, who shoots the eagle that feeds on Prometheus (Library 2.5.11).

Io in Egypt

At the Nile, in Ovid, Io knelt and raised her face to the sky, and Zeus begged Hera to end her punishment and promised he would never again give her cause for grief. Hera relented, and Io slowly lost her hair, horns and hooves and became a young woman again, afraid to speak lest she low like a cow (Metamorphoses 1.728–746). She bore Epaphus there (Apollodorus, Library 2.1.3). Apollodorus adds that Hera asked the Curetes to take the child away, and they did; Zeus killed the Curetes, and Io searched through Syria until she found Epaphus, then returned to Egypt and married Telegonus, who ruled the Egyptians (Library 2.1.3).

Io was also identified with the Egyptian goddess Isis. Herodotus notes that statues of Isis are shaped like a woman with a cow’s horns, as the Greeks picture Io (Histories 2.41), and Apollodorus says the Egyptians called Io by the name of Isis (Library 2.1.3). Ovid says the people of Egypt, dressed in linen, worship her as a goddess (Metamorphoses 1.747).

A Different Account of Io

Herodotus reports that Persian storytellers claimed the Phoenicians, not Zeus, were responsible for Io’s leaving Argos: Phoenician traders seized Io, the king’s daughter, with other women from the shore and carried them to Egypt (Histories 1.1).

Io Sources

Aeschylus, Prometheus Bound 1–2, 561–886; Apollodorus, Library 2.1.3–4, 2.5.11, 3.1.1; Herodotus, Histories 1.1, 2.41; Ovid, Metamorphoses 1.583–750.

See Also: Zeus, Hera, Hermes, Prometheus, Heracles, Inachus, Epaphus, Argus