Io/Origin

Origin
Io was, in Greek mythology, a priestess of Hera in Argos, a nymph who was seduced by Zeus, who changed her into a heifer to escape detection. His wife Hera sent ever-watchful Argus Panoptes, with 100 eyes, to watch her, but Hermes was sent to distract the guardian and slay him. Heifer Io was loosed to roam the world, stung by a maddening gadfly sent by Hera, and wandered to Egypt, thus placing her descendant Belus in Egypt; his sons Cadmus (Cadmus was also named as a son of Belus' brother Agenor) and Danaus would then "return" to mainland Greece. Io's father is generally given as Inachus, a river god credited with inaugurating the worship of Hera in the countryside around Argos, thus establishing her as an autochthonous spirit of the Argolid and thus by her nature the nymph of a spring, a Naiad. However, due to the Inachid genealogy being generally confused, other versions concerning her parentage existed as well. In some accounts, she is the daughter of the Argive Iasus, who himself was given either as the son of Argus Panoptes and Ismene, the daughter of Asopus, or of Triopas and Sosis; Io's mother in the latter case was Leucane. Io's father was called Peiren in the Catalogue of Women, and this figure might be a son of the elder Argus also called Peiras, Peiranthus or Peirasus in other sources. Io may therefore be identical to Callithyia, daughter of Peiranthus, as is suggested by Hesychius of Alexandria. Another of the myths is told most anecdotally by Ovid, in Metamorphoses. According to Ovid, one day, Zeus noticed the maiden and lusted after her. As Io tells her own story in Aeschylus' Prometheus Bound, she rejected his whispered nighttime advances until the oracles caused her own father to drive her out into the fields of Lerna. There, Zeus covered her with clouds to hide her from the eyes of his jealous wife, Hera, who nonetheless came to investigate. In a vain attempt to hide his crimes, Zeus turned himself into a white cloud and transformed Io into a beautiful white heifer. Hera was not fooled. She demanded the heifer as a present, and Zeus could not refuse her without arousing suspicion. Hera tethered Io to the olive-tree in the temenos of her cult-site, the Heraion, and placed her in the charge of many-eyed Argus Panoptes to keep her separated from Zeus. Zeus commanded Hermes to kill Argus; Ovid added the detail that he lulled all hundred eyes to sleep, ultimately with the story of Pan and Syrinx. Hera then forced Io to wander the earth without rest, plagued by a gadfly (Οἶστρος or oestrus: see etymology of "estrus") to sting her into madness. Io eventually crossed the path between the Propontis and the Black Sea, which thus acquired the name Bosporus (meaning ox passage), where she met Prometheus.