structural:summarization
In the Classical period

The cult of Hermes flourished in Attica, and many scholars writing before the discovery of the Linear B evidence considered Hermes to be a uniquely Athenian god. This region had numerous Hermai, or pillar-like icons, dedicated to the god marking boundaries, crossroads, and entryways. These were initially stone piles, later pillars made of wood, stone, or bronze, with carved images of Hermes, a phallus, or both. In the context of these herms, by the Classical period Hermes had come to be worshiped as the patron god of travelers and sailors. By the 5th century BC, Hermai were also in common use as grave monuments, emphasizing Hermes' role as a chthonic deity and psychopomp. This was probably his original function, and he may have been a late inclusion in the Olympic pantheon; Hermes is described as the "youngest" Olympian, and some myths, including his theft of Apollo's cows, describe his initial coming into contact with celestial deities. Hermes therefore came to be worshiped as a mediator between celestial and chthonic realms, as well as the one who facilitates interactions between mortals and the divine, often being depicted on libation vessels.

Due to his mobility and his liminal nature, mediating between opposites (such as merchant/customer), he was considered the god of commerce and social intercourse, the wealth brought in business, especially sudden or unexpected enrichment, travel, roads and crossroads, borders and boundary conditions or transient, the changes from the threshold, agreements and contracts, friendship, hospitality, sexual intercourse, games, data, the draw, good luck, the sacrifices and the sacrificial animals, flocks and shepherds and the fertility of land and cattle.

In Athens, Hermes Eion came to represent the Athenian naval superiority in their defeat of the Persians, under the command of Cimon, in 475 BC. In this context, Hermes became a god associated with the Athenian empire and its expansion, and of democracy itself, as well as all of those closely associated with it, from the sailors in the navy, to the merchants who drove the economy. A section of the agora in Athens became known as the Hermai, because it was filled with a large number of herms, placed there as votive offerings by merchants and others who wished to commemorate a personal success in commerce or other public affair. The Hermai was probably destroyed in the Siege of Athens and Piraeus (87–86 BC).

There was a popular, now lost play by the tragedian Astydamas with Hermes as the primary subject.