Mnemosyne — Classical Greek Myth Library

Hera, having taken the cow-Io as a gift, set Argus Panoptes to watch her. Classical tradition describes Argus as many-eyed: some eyes sleep while others wake, so that the cow never escapes unnoticed. Zeus, unwilling to confront Hera openly, sent Hermes to free Io. Hermes approached as a herdsman. He charmed Argus with talk and music—Apollodorus states briefly that Hermes killed him; later Roman narrative elaborates a long tale of Pan and Syrinx played on the pipes until every eye closed. When the watchman slept, Hermes struck him dead with a sword (or stone). From that killing the god received the standing Homeric epithet *Argeiphontes*, “Argus-slayer.” Hera took the eyes of the dead Argus and set them in the tail of her sacred bird, the peacock (etiology clearest in Roman telling; Greek cult already links Hera and the peacock). She then released a gadfly against Io, driving the cow into the wanderings treated in the Io entry. The Argus episode thus establishes Hermes as Zeus’s stealthy agent and as the slayer whose name Homer assumes without retelling the story.