Rosmerta · Maia · Esus · Lugus

“Of the gods, [the Gauls] most worship Mercury. They have many images of him, and regard him as the inventor of all the 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 Cæsar (summarizing Posidonius)[1]
Statuette of Mercury
Silver statuette of Mercury, found at Mâcon
(British Museum, London)

Mercury is the supreme god in Gaul. To be sure, it is Jupiter who reigns over the heavens and Mars who protects many ciuitates, but in Gaul, Mercury is master of his own domain. The epigraphic dedications that invoke him are more numerous than those that honour the Father of the Gods in many Gaulish provinces (including those of Gallia Belgica and Lugdunensis). As for statues, one of Gaul’s most famous was that dedicated to Mercury at the Puy de Dôme in Auvergne in what is now central France. The Arverni had given the Greek sculptor Zenodorus the commission of casting this monumental statue at the price of four million sesterces.


The first function that Cæsar notes is that of inventor of all the arts (omnium inuentorem artium). It is the role of creator and inventor with which Mercury is credited, while Minerva teaches the arts to mortals. Minerva presides in fact over industry and manufacturing (operum atque artificiorum), while Mercury’s sphere is a bit wider, including fine arts and all kinds of ruses. The Homeric Hymn tells how Hermes (Mercury) invented the lyre (ancestor of the harp and guitar, incidentally) the very day of his birth, before giving it up to his brother Apollo. According to this same text, Hermes presides over all kinds of trickery and theft, for the divine newborn also stole Apollo’s cattle only to disclaim the deed by lying with gusto.

Gaulish success at arts and crafts was considerable. While the historian Camille Jullian may have lamented the lack of artistic originality of the Gauls,[2] no one can dispute their technical skill (notably in metallurgy and ceramics).

Cæsar also indicates Mercury’s role as a guide of travellers (uiarum atque itinerum ducem). For us today, for whom life seems constantly in motion, the guide of travellers is more indispensable than ever. All who use a train, a car, a bicycle, an airplane, or even their own feet have reason to pray to Mercury. Anyone displaced or out of their familiar surroundings (such as immigrants, students or tourists) is under Mercury’s protection. And of course, life itself can be considered a journey; the analogy is so familiar as to have become a cliché.

The Gauls were accustomed to travel surprising distances as well: from Gaul to Delphi and Asia Minor, for example, or else to Egypt to serve as mercenaries. At the time, any journey was dangerous even if its aim was peaceful; imagine the gratitude with which the god would be thanked upon a safe return. Gauls only rarely indicated the reason why they honoured Mercury on their inscriptions. However, some stones dedicated to the god Mercury (and Rosmerta) for a son’s well-being[3] conjure up the image of parents worried for their child’s return.

The god’s role as provider of gain and of commerce (quaestus pecuniae mercaturasque) underscore his great importance in daily life. For better or worse, the best part of one’s day is spent in working to provide for life’s necessities. In order for such goods to come without too much trouble or to succeed in one’s business affairs, one prays to Mercury. Nor should he be seen as the the god of bosses alone. After all, to which god should a workingman call on for the success of a strike? Surely none other than Mercury.

Cæsar mentions only monetary gains. But like journeys, gains can be thought of as spiritual no less than material. “All things desire the Good,” as the philosophers have said,[4] and if this principle holds for material goods, it is just as true for spiritual goods.

Un bronze de Mercure
A bronze statuette of Mercury found at Reims.
(Musée Saint-Remi, Reims)


Mercury is normally depicted in Gaul in his classic Roman guise. His physique is that of a youngish athlete. In one hand he carries the caduceus, his winged staff with intertwined snakes; in his other hand, a money bag. The one symbolizes his role as herald of the gods and guarantor of peace; the other, the material and spiritual prosperity that he confers. Over his back he wears a traveller’s cloak, and on his head a petasus—a round winged cap. He may be accompanied by his favourite animals, namely the turtle, the rooster and the ram or goat.

Still, the Gaulish Mercury sometimes shows unexpected traits. He may appear bearded (as he sometimes is in Greek depictions). His head may even have three bearded faces, particularly in Belgica Secunda.

Origins and Family

The mother of Mercury is Maia, who is, according to Greek mythology, the daughter of a titan (namely Atlas) and the most important of the Pleiades. Mercury’s father is Jupiter; in myths, Mercury is always ready to carry out the will of his mighty father. He often appears as Jupiter’s messenger, the facilitator of his amours, and in one case the rescuer of his lover (namely Io, whom he frees by killing the giant Argos set to watch over her). It is Mercury, for example, who bears to Æneas the command to leave Dido and make his destiny in Latium.

Although Mercury has no regular spouse in Greek mythology, he is the frequent lover of Venus and the father of many gods, notably Hermaphroditus and (according to certain authors) Pan and Cupid.

In Gaul, the family or entourage of Mercury is a bit more extensive. His most important companion is Rosmerta, who often appears beside him in depictions and epigraphic invocations. The goddesses Visucia and Felicity also deserve mention; they may be aspects of Rosmerta, or else distinct divinities associated with Mercury.

A number of monuments depict Mercury alongside Cernunnos, the antlered god, who must have worked closely with Mercury both as provider of subterranean riches and as guardian of the souls of the departed. Mercury and Cernunnos are to be seen together on, for example, the silver cup found at Lyon (which also shows the eagle of Jupiter), as well as on the Reims altar, where Apollo and Mercury stand on either side of an enthroned Cernunnos.


Unlike Mars, Mercury is typically invoked in Gaul without any particular epithet, or just as ‘the god Mercury’ (in the dative, deo Mercurio—hence the name of this website!). This is notably the case on inscriptions evoking Rosmerta; the divine couple is nearly always called (the god) Mercury and Rosmerta, with no other Gaulish name.

Mercury does have a fair number of Gaulish or Latin epithets, however. In Gallia Belgica, one frequently finds Visucius (a name which perhaps has something to do with ravens[5]) and Cissonius (which perhaps signifies ‘of the chariots’). It is normally as ‘Mercury Visucius’ or ‘Mercury Cissonius’ that the god is invoked, but sometimes an inscription has ‘the god Visucius’ or ‘the god Cissonius’.

Most others are restricted in extent. In Germania Inferior, a favourite epithet of Mercury is Gebrinius; elsewhere we find Cimbrianus, Canetonnessis and Dubnocaratiacus. Many refer to a specific locale: ‘Mercury Vosegus’, of the Vosges massif in Alsace (also an epithet of Silvanus); ‘Mercury Dumias’, of the Puy de Dôme; ‘Mercury Bigentius’, of Bigentio, today’s Piesport (in the Moselle valley in Germany); ‘Mercury Arvernorix’, king of the Arverni.

‘Mercury Augustus’ is invoked frequently. On at least one occasion (in the Altbachtal in Trier, Germany), so too is ‘Mercury of the foreigners, of the non-citizens’ (Mercurius Peregrinorum).

For more information, please see this analysis of Mercury’s epicleses.

Mercury and Rosmerta – Mercury and Maia

See Rosmerta.


It is impossible to assimilate Mercury with Esus in a mechanical fashion, but the little that is known about the latter god does link him almost inextricably to Mercury. We shall therefore give a quick overview of the Esus file.

Two depictions, a poetic allusion, and a magical/medicinal formula make up practically the whole of our knowledge on Esus. Nonetheless, thanks to his Celtic name, the early date of his discovery[6] and his attestation in the French capital, Esus has been able to convince generations of researchers of his immense importance within the religion of the Celts.

Relief d’Esus sur le pilier des Nautes
The relief of Esus on the Pillar of the Boatmen
(Musée de Cluny; photograph by Clio20, CC-BY-SA)

Esus’ iconography is quite distinctive. In the Notre-Dame Cathedral of Paris, the Pillar of the Boatmen shows Esus, an axe in his hand, in the midst of cutting down a tree (said to be a willow). On an adjacent panel on the pillar is found Tarvos Trigaranus, a bull with three cranes or egrets. Another monument in Trier depicts an unnamed god in the same position; in the tree (again a willow) may be seen the head of a bull and three birds (perhaps geese). The resemblance is too striking to have been a coincidence: The god in Trier must be the same as the Parisian Esus.

Still, the relief of Esus in Trier is located on the back of a monument, the front of which is dedicated to Mercury with an illustration of Mercury and Rosmerta. A close link between Mercury and Esus is thus established, with no confusion between the two.

This link is reinforced by the poet Lucan’s mention of Esus in the Pharsalia. Enumerating and describing the peoples of Gaul, Lucan speaks of:

“those who pacify with blood accursed
savage Teutates, Hesus’ horrid shrines,
and Taranis' altars cruel as were those
loved by Diana, goddess of the north”

Lucan is accusing the Gauls here of making human sacrifices to the three gods he mentions. (He does so, however, rather casually; in fact, human sacrifice was probably all but obsolete by Cæsar’s time.) There is absolutely no reason to think that Teutates, Taranis and Hesus ever formed a triad, despite the most dogged efforts of modern scholars to demonstrate this. Lucan merely takes up a list of any old Gaulish deities, as he has just done of Gaulish tribes,[8] rivers, etc. He also is likely to have distorted the form of the name Taranis, which never appears as such on a monument in Gaul,[9] as well as that of Teutates, which he hellenizes from Toutatis. Be that as it may, the ancient scholiasts of Bern who annotated Lucan affirmed, first, that the Gauls offered people up to Esus by hanging them from a tree and then stabbing them (much like the victims offered to Odin, whom the Romans identified as Mercury as well); and secondly, that Esus was identified with either Mars or Mercury depending on the context. Here again we find the tree, as well as Mercury.

Finally, Marcellus Empiricus records a late Gaulish formula in De medicamentis that is supposed to be helpful for a throat-ache:

xi exugri conexugri glion Aisus scrisumio uelor exugri conexugri lau

The formula invokes the aid of Aisus. Gaulish remains a difficult language to interpret, but following Léon Fleuriot’s analysis for the most part, the formula would mean something like, “Go, get out; I want to spit out, Aisus, the stuff that’s sticking; go, get out”.[10] Why is it that Esus intervenes here in a medical matter? Is this one of his regular domains (as it is sometimes of Mars)? We cannot say.

This is the essence of what is known about Esus. The god may also appear from time to time under slightly different names: according to Xavier Delamarre, the name Esumopas means ‘Esus-Child’, Esuateros ‘Esus-Father’; and the element Esu- appears in many other proper names such as Esunertus (‘Esus-strength’—which, be it noted, is the name of a mortal).

The image of Esus cutting down the willow, accompanied by Tarvos Trigaranus and his birds, no doubt illustrates a Gaulish myth that has now been lost. What is the significance of the willow? Could it be the tree of life, as it is sometimes suggested? Does Esus incarnate the destructive aspect of divinity, like Shiva? The willow is a tree much frequented by egrets, which eat the insects disturbed by the movement of a buffalo or bull.[11] What role does this ecological fact play in the myth? Is the act of Esus aimed at breaking this equilibrium? and for what reason? As Aimé Césaire declares, “I fell the trees of Paradise”—the statement comes at the end of a poem as heavily ambiguous as the figure of Esus himself.[12]

As Edith Mary Wightman remarks concerning this lost mythology, “the attempts to portray it in an organized fashion, as at Paris and Trier, belong to the early efforts at Romanization made in the 1st century and do not seem to have been repeated”.[13] Early Gauls considered this mythology significant, but soon its place would be taken by that of Mercury and Mars.

The best website on Esus is probably About Esus, by Michael J. Dangler.

Mercury and Lugus

Something should also be said about the identification of the Gaulish Mercury as Lugus. Without doubt, Lug Lámfada is a figure of the first importance among the Tuatha Dé Danann, the divine clan of Irish mythology. The problem, however, is that we so often assume him on that basis to have been a pan-Celtic god whose worship was supposedly implanted everywhere the Celts went. Granted, some inscriptions do attest the cult of Lucus and the Lugoves in Iberia and among the Helvetii; the phrase luge dessummiíis recurs on a Gaulish-language defixio; Lleu Llaw Gyffes is a major figure in mediæval Welsh mythology; and a host of place names contain the root lugu-, notably including Lugudunum (Lyon). One need only add that the federal feast of the Three Gauls took place in Lyon on the 1st of August, the feast-day of Lugnasad (the Irish feast that Lug consecrated to his foster mother Tailtiu), for the great bulk of writers on this subject to accept the hypothesis of Lugus as the universal Celtic god underlying the Gaulish Mercury.

But all this evidence is circumstantial, and some of it dubious. The federal feast of the Three Gauls was dedicated to Rome and Augustus, with no link to Mercury (nor, for that matter, to a Gaulish Tailtiu). The date of the federal feast was chosen to commemorate Cæsar Augustus’ victory at Alexandria. The root lugu- is difficult to interpret; it might mean ‘a vow’, ‘a raven’, or ‘light’—in any case it need not refer to a god. No one really knows the meaning of the phrase luge dessummiíis. Here too, luge might be a common noun just as well as the name of a god, and in either case, the nominative form would not be Lugus, but probably luxs or lugis. The “solution adopted by most commentators”, according to Xavier Delamarre, is to take the word luge to mean “by the vow”.[14] If the Irish Lug and the Welsh Lleu Llaw Gyffes date back to the the most important ancient god in the British Isles, why is it that not the least trace of him has been found in classical Britain? We should expect to find numerous inscriptions to ‘Mercurius Lugus’, but there is not one to be found anywhere.

Let us acknowledge that the only thing proven is that the Lugoves were worshipped in Iberia and that (in at least one case) an inscription was also dedicated to them in Helvetia. It must be said that scores of other gods are attested as weakly as this. For the present, let us lift the burden of modern schematization from the shoulders of the poor Lugoves. When speaking of the great god of the ancient Celts, let us rather be prudent and worship him under the name we know: Mercury.


Julius Cæsar’s excursus ethnographica, summarizing Posidonius, directly affirms Mercury’s preeminence in Gaul, which we would in any case have suspected thanks to the great number of his depictions and inscriptions. He is invoked for the success of commercial ventures, but also for those of voyages, including the voyage that each soul must take into the Otherworld. Mercure is the architect, not only of the material gains that are the basis of human prosperity (along with his colleagues Rosmerta and Cernunnos), but also of spiritual gains. With Hercules and Apollo, he presides over eloquence; with Minerva, over crafts and artifice. Like Lug Lámfada, who is considered his counterpart in Irish mythology, Mercury is the samildánach, master of all arts. Numerous traditions link Mercury to eminent places across Gaul, such as the Puy de Dôme and the Vosges. In Gaul, Mercury is truly master of his own domain.


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