Overview
Io was, in Greek mythology, one of the mortal lovers of Zeus. An Argive princess, she was an ancestor of many kings and heroes, such as Perseus, Cadmus, Heracles, Minos, Lynceus, Cepheus, and Danaus. The astronomer Simon Marius named a moon of Jupiter after Io in 1614.
Because her brother was Phoroneus, Io is also known as Phoronis (an adjective form of Phoroneus: "Phoronean"). She was sometimes compared to the Egyptian goddess Isis, whereas her Egyptian husband Telegonus was Osiris.
Family
In most versions of the legend, Io was the daughter of Inachus, though various other purported genealogies are also known. If her father was Inachus, then her mother would presumably have been Inachus' wife (and sister), the Oceanid nymph Melia, daughter of Oceanus, although this is nowhere stated.
Io's father was called Peiren in the Catalogue of Women, and by Acusilaus, possibly a son of the elder Argus, also known as Peiras, Peiranthus or Peirasus. Io may therefore be identical to Callithyia, daughter of Peiranthus, as is suggested by Hesychius of Alexandria.
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