In Ancient Greece, the God Hermes was a phallic god associated with fertility, luck, roads and borders; he was also known as the messenger of the Gods, and later as the patron of markets and merchants, travellers and athletics. His name is thought to derive from the Greek word herma, a boundary stone or pillar of square rectangular form topped by the head of Hermes, and with ithyphallic male genitals further down on the pillar. It may be that the connection went the other way - from deity to pillar. These herms were placed at strategic points along roadsides and crossroads, marking boundaries, and also placed outside houses, gymnasia and in markets, in order to ensure the fertility of herds and flocks, and to bring luck.
In Classical and Hellenistic art, Hermes is depicted as a handsome young, beardless god with short curled hair but on hermai he is portrayed - as in Archaic Greek art- as a mature male figure with elaborately curled long hair and beard. The herm was a powerful monument - on the eve of the Athenian expedition to Syracuse in 415 BC during the Peloponnesian War, the Athenian herms were vandalised - an act of shocking impiety. Both Syracusan saboteurs and anti-war Athenians were suspected; Alcibiades, the flamboyant pupil of Socrates, was famously accused and the episode led indirectly to the death of Socrates.
The herm we have here is a fine example made in the early Imperial period in Rome; it is a copy of a famous sculpture, the Hermes Propylaios (Hermes Before-the-Gates) which stood at the entrance to the Acropolis at Athens. The original, by the renowned and gifted Athenian sculptor Alcamanes in the second half of the 5th Century B.C., is known to us from literary descriptions, and from later copies. Pausanias, the 2nd Century A.D. Greek traveller, wrote what can be described as a guidebook for tourists, the 'Description of Greece', in which he gave a description of each city he visited with a historical synopsis followed by a detailed account of its monuments; the Hermes Propylaios is referred to.
During the Roman period, copies were made of famous Greek masterpieces, many of which are known to us only through literary sources and later copies. For a similar copy of the Hermes Propylaios of Roman date, cf: A. Stewart, Greek Sculpture, Yale, 1990, pp. 267-8, pl. 400. It was discovered at Pergamon in 1903 and bears the inscription 'You will recognise Alkamanes' fine statue, the Hermes Before-the-Gates. Pergamios set it up' and beneath the dedicatory inscription is the maxim 'know thyself'.