In the Greek mythology Io was a priestess of Hera and daughter of Inaco (king of Argo city). Io was beautiful and Zeus fell in love with her. The legend tells Zeus met her disguised himself as a cloud in order not to be discovered by his wife Hera. Hera, made suspicious, came down to the earth to verify by herself. Zeus, seeing her coming, transformed Io into a cow. Hera perceived the deception and asked Zeus to present her with that cow.  Zeus could not refuse and Io, transformed in cow was sent by Hera to a grazing land guarded by Argo, a monster, never sleeping, with100 eyes, 50 opened the day and the other 50 the night. Zeus commissioned his son Hermes to free Io at any cost. Hermes disguised himself as a shepherd went to the grazing of Io and Zeus and started to play his flute. After a while, by mean of that music, Argo fell asleep closing all his eyes. Then Hermes killed Argo and freed Io. Hera put Argo's 100 eyes on the tail of peacock (animal holy to her) and wanting to revenge herself sent a gadfly to Io. Io, in order to escape the gadfly, dived into a see called, after that, Ionian see. After many vicissitudes Io came to Egypt, the human appearance and gave birth to Epafo, son of Zeus.

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