Greek Mythology Notes
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Io (Nymph)

nymph
Ἰώ
Priestess turned white cow who roamed the earth

Io was a priestess of Hera transformed into a white cow by Zeus to hide their affair — she wandered in torment across the world before being restored in Egypt.

The Myth

Zeus loved Io and transformed her into a cow to hide the affair from Hera. Hera demanded the cow as a gift and set hundred-eyed Argus to guard her. After Hermes killed Argus, Hera sent a gadfly to torment Io. She fled across continents — the Ionian Sea and the Bosphorus ("ox-ford") are named for her crossing. In Egypt, Zeus restored her human form. She bore Epaphus, ancestor of Danaus, the Danaids, Perseus, and Heracles — making her the matriarch of the greatest heroic lineage.

Parents

Inachus (river god)

Children

Epaphus (by Zeus)

Symbols

white cowgadflywanderinghundred-eyed guard

Fun Fact

Both the Ionian Sea and the Bosphorus ("ox-ford") are named for Io — geography permanently marked by her bovine wandering.

Words We Inherited

English words and phrases that trace back to this myth:

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