1. Local traditions.
--The place to which the legends of lo belong, and where she was closely connected with the worship of Zeus and Hera, is Argos.
The chronological tables of the priestesses of Hera at Argos placed Io at the head of the list of priestesses, under the name of Callirhoe, or Callithyia. (Preller, de Hellan. Lesb.
She is commonly described as a daughter of Inachus, the founder of the worship of Hera at Argos, and by others as a daughter of Iasus or Peiren. Zeus loved Io, but on account of Hera's jealousy, he metamorphosed her into a white cow. Hera thereupon asked and obtained the cow from Zeus, and placed her under the care of Argus Panoptes, who tied her to an olive tree in the grove of Hera at Mycenae. But Hermes was commissioned by Zens to deliver Io, and carry her off. Hermes being guided by a bird (ἱέραξ
), who was Zeus himself (Suid. s. v. Ἰώ
), slew Argus with a stone. Hera then sent a gad-fly. which tormented Io, and persecuted her through the whole earth, until at length she found rest on the banks of the Nile. (Apollod. 2.1.2
; Hyg. Fab. 145
; comp. Verg. G. 3.148
This is the common story, which appears to be very ancient, since Homer constantly applies the epithet of Argeiphontes (the siaver of Argus) to Hermes.
But there are some slight modifications of the story in the different writers. Some, for example, place the scene of the murder of Argus at Nemea (Lucian, Dial. Deor.
3; Etymol. Mag. s. v. Ἀφέσιος
). Ovid (Ov. Met. 1.722
) relates that Hermes first sent Argus to sleep by the sweetness of his music on the flute, and that he then cut off the head of Argus, whose eyes Hera transferred to the tail of the peacock, her favourite bird. (Comp. Moschus, Idyll.
A peculiar mournfill festival was celebrated in honour of Io at Argos, and although we have no distinct statement that she was worshipped in the historical ages of Greece, still it is not improbable that she was. (Suid. l.
c.; Palaephat. p. 43; Strab. xiv. p.673
There are indeed other places, besides Argos, where we meet with the legends of Io, but they must be regarded as importations from Argos, either through colonies sent by the latter city, or they were transplanted with the worship of Hera, the Argive goddess. We may mention Euboea, which probably derived its name from the cow Io, and where the spot was shown on which Io was believed to have been killed, as well as the cave in which she had given birth to Epaphus. (Strab. vii. p. 320; Steph. Byz. l. s. Ἄργουρα
; Etymol. Mag. s. v. Εὔβοια
.) Another place is Byzantium, in the foundation of which Argive colonists had taken part, and where the Bosporus derived its name, from the cow Io having swam across it. From the Thracian Bosporus the story then spread to the Cimmerian Bosporus and Panticapaeum. Tarsus and Antioch likewise had monuments to prove that Io had been in their neighbourhood, and that they were colonies of Argos. Io was further said to have been at Joppa and in Aethiopia, together with Perseus and Medusa (Tzetz. ad Lycoph.
835, &c.); but it was more especially the Greeks residing in Egypt, who maintained that Io had been in Egypt, where she was said to have given birth to Epaphus, and to have introduced the worship of Isis, while Epaphus became the founder of a family from which sprang Danaus, who subsequently returned to Argos.
This part of the story seems to have arisen from certain resemblances of religious notions, which subsequently even gave rise to the identification of Io and Isis. Herodotus (i. l, &c., 2.41) tells us that Isis was represented like the Greek Io, in the form of a woman, with cows' horns.