Io was the daughter of a rivergod．She was loved，run after and won by Zeus．Hera became so greeneyed that she flew down from Olympus one day to pay her rival back ．Zeus，however，had foreseen her arrival and changed Io into abeautiful white little cow．Seeing through the trick，Hera asked for the cow as a present and Zeus had to give in to her wish ．Then she left the cow to the care of a hundredeyed monster，Argus．Argus' eyes were ever open and no escape was possible．Unable to bear to see her so unhappy，Zeus sent Hermes down todestroy the monster．Dressed up as a shepherd，Hermes lulled Argus to sleep with his sweet songs and long stories，then killed him and set Io free．But Hera's anger was not to be calmed downyet．She sent a gadfly to attack the cow and drive her from land to land．In her misery the cow passed over the strait which divides Europe and Asia．In this way the strip of water got itsname Bosporus ，the way of the cow．She wandered over thesea，which by chance got from her its name the Ionian Sea ．In the end she arrived in Egypt where she was turned back into hernatural form ．She settled down and gave birth to a son，Some of her children remained in Egypt and ruled as kings for a longtime.