Mercury and Argus by Jacob Jordaens - Lyon France

This painting of Mercury and Argus (!620) is by Jacob Jordaens, and located in The Museum of Fine Arts, Lyon France.

Zeus falls in love with Io, then in order to hide the affair from Hera, turns Io into a cow. Hera is not fooled and asks Zeus to gift her the cow, which Zeus reluctantly agrees to. Having gained possession of the cow, Hera instructs the  hundred-eyed giant Argus Panoptes to guard the cow. Argus ties Io to a tree and guards her closely, allowing only a few of his eyes to sleep at a time. However, Zeus, desperate to free Io, sends Mercury to rescue her. Mercury using his cunning, disguises himself as a shepherd and plays music on a flute, or lyre to lull Argus to sleep. As all of Argus’s eyes finally close, Mercury seizes the moment and kills him, freeing Io. Hera honors Argus by placing his eyes on the tail of the peacock, her sacred bird.