The Roman god Mercury was based almost entirely on the Greek messenger god Hermes.
To the Romans, however, his most important role was not as a diplomat or even as a messenger from the gods. Mercury was the god of commerce, putting him at the center of Roman life.
As the Republic expanded its borders and became a vast empire, Mercury’s role as the patron of merchants and the protector of cargo became more and more important. Rome relied on goods from around the known world, and Mercury made sure they enriched the city.
From the capital’s central public building to the farthest reached of Gaul, Mercury was recognized as one of the pillars of the Roman way of life.
Unlike many of the gods of Rome, there was no early Italian source for Mercury.
The Etruscan god Turms was very similar, as he was also a god of commerce and an intermediary between the gods and mankind. Turms, however, was not a native god of Italy either.
Therefore, the characterization and mythology of Mercury remained almost entirely unchanged. The only obvious difference in Rome was his name.
Mercury comes from the Latin verb mercari, “to trade.” His primary role in Roman culture was as the god of merchants and commerce.
The Greeks, too, had seen the messenger god as an important deity in trade. Hermes watched over all travelers, so the merchants that moved goods throughout the Mediterannean were under his protection.
Between the feuding city-states of Greece, however, he had been most important as a diplomat. Rome soon conquered and assimilated its closest neighbors and established itself as a nation that relied on the movement of goods more than diplomatic relations.
Rome could not function without its trade routes. As the city’s population grew it needed grain from Egypt, vegetables from Tuscany, wood from Gaul, and metals from Spain and Britain.
As the god who protected travelers, Mercury was essential in making sure that shipments of all these goods arrived steadily from throughout Rome’s territories. Without his favor, Roman culture would collapse.
He was especially important in the grain trade. Any interruption in the flow of grain from Egypt led to shortages of bread among the poor of Rome, a situation that could easily lead to civil unrest and violence.
While Mercury was important to the Roman way of life, they believed that other people held him in even higher regard.
When writing about the people of Gaul, Julius Caesar said:
They worship Mercury in particular, as their god and have many images of him, and regard him as the inventor of all arts. They consider him the guide of their journeys and marches, and believe him to have great influence over the acquisition of gain and mercantile transactions.
-Julius Caesar, The Conquest of Gaul
Of course, the arrival of Mercury in Gaul did not occur until after it was occupied by Rome, so Caesar’s belief that the people of central Europe worshipped Roman gods, including Mercury, seems unusual.
However, the Romans often interpreted foreign gods as different versions or aspects of their own. Just as they had seen the Greek gods as aspects of native Italian deities centuries before, the Romans of Caesar’s time believed that other cultures simply worshipped the same gods under different names.
The Romans also had trouble distinguishing between the many cultures they encountered north of the Alps. The various Germanic tribes, including the Gauls and Celts, were often grouped into broad categories.
Thus, when Caesar wrote about the worship of Mercury in Gaul he was actually talking about many different gods, none of whom were Mercury at all.
In Celtic regions, he was likely conflated with the god Lugus. Little is known about Lugus’s mythology and role, but his importance can be seen in the number of places associated with him and the fact that he was the consort of Rosmerta, the goddess of fertility.
Among the Germanic people, the Romans associated Mercury with Wotan. The Germanic form of Odin, Wotan was the chief of the gods but associated with the god of commerce because he was often depicted as a traveller.
As Roman influence in Germanic regions increased, the associations between their gods were strengthened. Local gods took on more Roman attributes and in Rome itself Mercury became the god more associated with Gaul and the Celts.
The Latin language had many words that were closely tied to the god of trade.
Several of these words have been passed down into English usage, continuing the influence of Roman religion and culture in the modern age. These include:
- The planet Mercury – Named for the swiftest of the gods because of the speed at which it orbits the sun.
- Words associated with trade – These include merchant, merchandise, and market, all of which come from the same Latin word as the god’s name.
- The metal mercury – Also known as quicksilver, the metal was named after the god because its liquid state allows it to move smoothly and quickly.
- Mercurial – The adjective means quick or spritely in addition to changeable.
- The plant mercury – A group of weedy plants native to Europe, North Africa, and Asia, mercury gets its name from the fact that one of the most common varieties is poisonous to cattle, bringing to mind the legend of Mercury stealing Apollo’s cattle and killing two.
In the city of Rome, the Temple of Mercury was built in a surprising location. It was dedicated in 495 BC within the Circus Maximus.
The Circus Maximus was the city’s first and largest entertainment venue. It routinely hosted chariot races and ludi, or public games.
This may seem like a space that is disconnected to religious life, but such events were tied to the worship of certain gods and their festivals. Archaeological evidence actually suggests that the Circus Maximus was built around existing shrines to further tie worship and entertainment together.
Even if the ludi were not dedicated to the gods, the Circus Maximus was still a logical place to center the worship of Mercury in the city of Rome.
The god was known for his speed, so chariot racers often associated their sport with him. Mercury was said in mythology to often best the other gods in their own games, so he was linked with athleticism.
The Circus Maximus also served as a major commercial center within the city. Vendors and hawkers filled the area so during events the venue took on the tone of a large market.
In fact, the Circus was next door to the city’s cattle market. Mercury had stolen the cattle of Apollo, and at times the racetrack was used to temporarily house the animals that would be traded later in the day.
In such a busy atmosphere, the thieves and tricksters who prayed to Mercury thrived as well. Mercury was not as closely associated with theft as his Greek counterpart had been, but it was still an important part of his legend.
The position of the Circus Maximus within the city of Rome also made it a natural place to worship the god of diplomacy and messengers.
The Temple of Mercury was dedicated in a year that saw major social unrest in Rome. The noble patricians and lower-status plebians fought for influence in the Senate.
The Circus Maximus had been built almost precisely in between the Capitaline Hill, the traditional home of the patrician class, and the Aventine Hill, the stronghold of plebian political power. The placement of Mercury’s temple between these two feuding factors highlighted his role as diplomat and negotiator.
While most of Mercury’s mythology was taken directly from Greek sources, a few stories were told in Rome alone.
One of these involved the journey of Aeneas. The son of Venus, he had fled Troy at the end of the Trojan War to settle in Italy, becoming a founding king and an ancestor to Romulus and Remus.
The Roman story of Aeneas was modelled after that of Odysseus, and Mercury appeared to the Roman hero just as he had to the Ithacan kind. In the Aeneid, Mercury appears to Venus’s son to remind him to continue on his mission to fulfil his destiny of becoming one of Rome’s founders.
Mercury also appears in his role as a psychopomp in Ovid’s Fasti.
In the poem, he is tasked with escorting a nymph named Larunda into the Underworld. He falls in love with her, however, and she gives birth to his children in the land of the dead.
Their invisible twins were called the Lares and served as protective gods. The Lares were likely an older aspect of Roman mythology, but Ovid gave them an origin that tied them to one of the great Olympian deities.
In Rome, Mercury was the messenger of the gods, the patron of travellers and diplomats, a psychopomp, and the god of tricksters and thieves. Most importantly, however, he was the god of commerce, merchants, and trade.
Rome relied on goods from around its territories for more than just wealth. Without imported grain, metal, and wood, the city could not support its ever-growing population.
With few independent neighbors to negotiate with, Mercury was primarily the patron of the trade that made the city of Rome and its vast empire possible.
His most important role as a diplomat was sometimes between the people of Rome themselves. The placement of his temple in the Circus Maximus tied him not only to racing and commerce, but also placed him as a mediator in the feuds between the patrician and plebian classes.
Outside of Italy, he was considered the chief god. This was because the Romans associated him with Celtic and Germanic gods like Lugan and Woden, making him the highest member of the Gallic pantheons.
Mercury’s importance in Rome is evident in the number of words used in modern English that are still influenced by him. His speed, association with commerce, and the tricks he played are remembered in the English language to this day.