Hermes began as a god with strong chthonic associations: a psychopomp leading souls between upper and lower worlds. That role expanded to roads, boundaries, travelers, sailors, and commerce. Hermai — squared pillars with a head (and often a phallus) — marked roads, graves, and household entrances as protective boundary stones.

As divine messenger he conveys word among Olympus, the underworld, and mortals. He is also patron of flocks and shepherds, of cunning speech and invention, and of thieves — traits already vivid in the Homeric Hymn to Hermes, which tells of his infant cattle-raid and invention of the lyre.

Son of Zeus and the Pleiad Maia, Hermes is born on Mount Cyllene in Arcadia. He escorts Priam to Achilles, leads Persephone from Hades at Zeus's command, and serves as guide and trickster throughout epic and drama. Archaic art often shows him bearded and traveler-clad; Classical and Hellenistic images prefer a youthful, athletic, beardless type.

Standard attributes are the caduceus (kerykeion), winged sandals, and the traveler's petasos. Romans identified him with Mercury; later antiquity also folded him into philosophical Hermes Trismegistus traditions distinct from the Olympian cult figure.

Arcadia, especially Cyllene and Pheneus, claimed early and strong cult. Athens filled its streets with herms, and Hermes shared household and civic honours with other protective deities. Festival and local lore also remember him as a plague-averting shepherd god who circled city walls with a ram or calf.

Because he crossed every threshold — market, road, death, and speech — Hermes remained one of the most pervasive Olympians in daily Greek life.