Mercury, Argus & Io

On the right side of the relief, Mercury (or his Greek equivalent, Hermes) sits with his shepherd’s pipe, about to lull the hundred-eyed cowherd Argus to sleep with his music. Mercury plans to steal the heifer behind Argus. This young cow is actually the nymph Io, with whom Zeus is in love. Zeus has changed her into a heifer in order to conceal her from his wife, Hera. However, Hera finds out, makes Zeus give her the heifer as a present and sets Argus to guard her. Zeus asks Mercury to lull Argus to sleep with his music and then kill him so that Zeus can get Io back. Hera is unable to save Argus, but does prevent Io from returning to Zeus.

Additional information:
In this story, Mercury is an evil figure. His music and Zeus’s lust lead to the murder of the faithful cowherd, Argus. This was a warning to the city authorities to guard against greed and lust and the evil deeds to which the abuse of music might lead. This relief on the theme of bad governance is a pendant to the relief showing Amphion.