Mercurius (Mercury) is the God of commerce. The guild of merchants honored Mercurius at his temple near the Circus Maximus on his festival, the Mercuralia, on May 15. They also sprinkled themselves and their merchandise with sacred water in a ceremony at the Capena Gate.
A common epithet of Mercurius was Bonus Mercurius very similar to optimus.
When Mercurius became identified with the Greek Hermes, he took on the duties of messenger of the Gods, Psychopompus who guides the souls of the dead through the Underworld, and God of sleep and dreams. He also became God of thieves and trickery, owing to a trick he had played on Apollo by stealing and hiding the Sun God's cattle. His serpent-twined staff (two serpents), the caduceus, was originally a magician's wand for wealth (and is often confused with the "rod of Aesculapius", entwined with a single serpent) but became identified later as a herald's staff. But Mercurius has many aspects, attributes, names and epithets.
Mercury did not appear among the numinous di indigetes of early Roman religion. Rather, he subsumed the earlier Dei Lucrii as Roman religion was syncretized with Greek religion during the time of the Roman Republic, starting around the 4th century BC. From the beginning, Mercury had essentially the same aspects as Hermes, wearing winged shoes talaria and a winged petasos, and carrying the caduceus, a herald's staff with two entwined snakes that was Apollo's gift to Hermes. He was often accompanied by a cockerel, herald of the new day, a ram or goat, symbolizing fertility, and a tortoise, referring to Mercury's legendary invention of the lyre from a tortoise shell. Like Hermes, he was also a messenger of the gods and a god of trade, particularly of the grain trade. Mercury was also considered a god of abundance and commercial success, particularly in Gaul. He was also, like Hermes, the Romans' psychopomp, leading newly-deceased souls to the afterlife. Additionally, Ovid wrote that Mercury carried Morpheus' dreams from the valley of Somnus to sleeping humans.
When they described the gods of Celtic and Germanic tribes, rather than considering them separate deities, the Romans interpreted them as local manifestations or aspects of their own gods, a cultural trait called the interpretatio Romana. Mercury in particular was reported as becoming extremely popular among the nations the Roman Empire conquered; Julius Caesar wrote of Mercury being the most popular god in Britain and Gaul, regarded as the inventor of all the arts. This is probably because in the Roman syncretism, Mercury was equated with the Celtic god Lugus, and in this aspect was commonly accompanied by the Celtic goddess Rosmerta. Although Lugus may originally have been a deity of light or the sun (though this is disputed), similar to the Roman Apollo, his importance as a god of trade and commerce made him more comparable to Mercury, and Apollo was instead equated with the Celtic deity Belenus
Mercury's temple in the Circus Maximus, between the Aventine and Palatine hills, was built in 495 BC. This was a fitting place to worship a swift god of trade and travel, since it was a major center of commerce as well as a racetrack. Since it stood between the plebeian stronghold on the Aventine and the patrician center on the Palatine, it also emphasized the role of Mercury as a mediator. Because Mercury was not one of the early deities surviving from the Roman Kingdom, he was not assigned a flamen ("priest"), but he did have a major festival on May 15, the Mercuralia. During the Mercuralia, merchants sprinkled water from his sacred well near the Porta Capena on their heads.
Mercurius Artaios, a combination of Mercury with the Celtic god Artaios, a deity of bears and hunting who was worshiped at Beaucroissant, France.
Mercurius Arvernus, a combination of the Celtic Arvernus with Mercury. Arvernus was worshiped in the Rhineland, possibly as a particular deity of the Arverni tribe, though no dedications to Mercurius Arvernus occur in their territory in the Auvergne region of central France.
Mercurius Cissonius, a combination of Mercury with the Celtic god Cissonius, who is written of in the area spanning from Cologne, Germany to Saintes, France.
Mercurius Esibraeus, a combination of the Iberian deity Esibraeus with the Roman deity Mercury. Esibraeus is mentioned only in an inscription found at Medelim, Portugal, and is possibly the same deity as Banda Isibraiegus, who is invoked in an inscription from the nearby village of Bemposta.
Mercurius Gebrinius, a combination of Mercury with the Celtic or Germanic Gebrinius, known from an inscription on an altar in Bonn, Germany.
Mercurius Moccus, from a Celtic god, Moccus, who was equated with Mercury, known from evidence at Langres, France. The name Moccus ("pig") implies that this deity was connected to boar-hunting.
Mercurius Visucius, a combination of the Celtic god Visucius with the Roman god Mercury, attested in an inscription from Stuttgart, Germany. Visucius was worshiped primarily in the frontier area of the empire in Gaul and Germany. Although he was primarily associated with Mercury, Visucius was also sometimes linked to the Roman god Mars, as a dedicatory inscription to "Mars Visucius" and Visucia, Visicius' female counterpart, was found in Gaul
- ↑ See Brouwer, Bona Dea, p.246.
2. Graves, Robert. The Greek Myths. Vol I. London: Penguin, (1960) p. 65