Io

Io was born in Argos, the greatest city of the Argolid, the region of the Peloponnese that jutted into the Aegean Sea. Her father was Inachus, the river god whose waters ran through the plain of Argos, or in some tellings Iasus, a descendant of the first king Phoroneus. She was a priestess of Hera, the queen of Olympus and wife of Zeus, the king of the gods who ruled with his thunderbolt, and her beauty was so extraordinary that Zeus himself desired her. The king of the gods came to her in secret, or in some versions he pursued her through the fields of Argos until she could run no further, and from their union came a child that would shake the world. But Hera was not deceived. She watched her husband with the eyes of a goddess who had learned to recognise every trick, and when she found Io, the girl was already transformed.

The stories disagree about who changed Io into a cow. In some tellings, Zeus transformed her into a white heifer to hide her from his wife, hoping that Hera would not recognise the priestess beneath the horns and hide. In others, Hera herself struck the girl with divine power, turning her into a beast as punishment for daring to share her husband's bed. Either way, the result was the same: Io stood in the grove of Hera at Mycenae, a white cow with horns curved like the crescent moon, her human mind trapped inside the body of an animal. Hera approached Zeus and asked for the heifer as a gift. Zeus could not refuse without revealing his deception, and so he gave Io to his wife. Hera then appointed Argus Panoptes, the hundred-eyed giant who was the son of Gaia, the earth goddess, as the cow's guardian. Argus tied Io to an olive tree in the sacred grove and watched her with eyes that never closed all at once, some always awake while others slept, so that no one could approach her unseen.

Zeus could not bear to see Io suffer, and he sent Hermes, the messenger god who moved between Olympus and the mortal world with winged sandals and a caduceus, to free her. Hermes came to Argus disguised as a shepherd and sat beside him, playing music on his reed pipes and telling stories so long and so captivating that the giant's eyes began to close one by one. When the last eye shut, Hermes struck, and Argus Panoptes fell dead. Hera took the hundred eyes of her fallen servant and placed them upon the tail of her favourite bird, the peacock, where they remain to this day as the iridescent spots that decorate its feathers. But Hera was not finished. She sent a gadfly, a stinging insect whose bite was like fire, to torment Io without rest. The gadfly drove the heifer mad with pain, and she bolted from the grove and ran.

Io's flight was the longest wandering of any mortal in Greek myth. She ran north from Argos, across the plains of Thessaly, through the mountains of Thrace, and came at last to the narrow strait that separates Europe from Asia, the passage that would be called the Bosporus, the ox-passage, forever after. She swam across the channel, her hooves striking the waves, and continued eastward through the lands of the Scythians and the Cimmerians. She climbed the mountains of Caucasus, where Prometheus, the Titan who had stolen fire for mankind and was punished by being chained to a rock where an eagle ate his liver each day, called out to her from his chains. He told her that her suffering would end, that she would be restored to human form in Egypt, and that one of her descendants would be Heracles, the greatest hero of Greece, who would one day free Prometheus from his own torment. He told her to follow the south wind, and she ran on.

She crossed the Ionian Sea, the waters that would bear her name, and came to the shores of Egypt. There, on the banks of the Nile, Zeus touched her with his hand and restored her human form. She gave birth to a son, Epaphus, whose name means "touch," for he was born from the touch of a god. The Egyptians worshipped Io as the goddess Isis, and her son as the sacred bull Apis. She married Telegonus, the king of Egypt, and her descendants ruled the land for generations. Her grandson Danaus would one day return to Greece with his fifty daughters, the Danaids, to reclaim the throne of Argos. Her other descendants included Cadmus, the Phoenician prince who slew the dragon of Ares and founded Thebes, and through them the line stretched to Perseus, the slayer of the Gorgon Medusa, and Heracles, the hero who completed twelve impossible labours and became a god. The moon-marked cow had become the mother of heroes.