Among the many names and faces that make up the Roman pantheon are gods borrowed from the religions of other cultures. One intriguing import, who joined the divine panoply around the 1st century AD, was the mysterious bull-slayer Mithras, a deity associated with contracts in Persia long before his adoption – and adaptation – by the Romans.
With a myth connected to regeneration, Mithras came to be worshipped both in Rome and across the provinces of the empire. The far-reaching extent of the cult and its cave-like sanctuaries, or mithraea – found everywhere from Spain to Syria – is reflected in the international approach of a project that is bringing a new presentation of Mithras to three different countries. The Musée Saint-Raymond (MSR) in Toulouse, France, the Musée Royal de Mariemont in Belgium (the previous hosts), and the Archäologisches Museum Frankfurt, Germany, have partnered for the project, which marks the first time in Europe that the subject of Mithras across the Roman Empire is explored through dedicated exhibitions. Each shares a single theme, but they are different exhibitions: for example, the MSR exhibition (on view until October) includes sculptures from Spain and Portugal and a section on the god’s impact in pop culture, while the third and final event, which will take place in Frankfurt, will deal more specifically with the archaeology of the mithraea on the Rhine-Danube limes (frontier). The whole endeavour is served by a remarkable selection of emblematic works and a narrative built on the most recent archaeological discoveries and studies in classical antiquity. As these various sources show, the god’s image spread far and wide – but how did Mithras reach Rome?
Mithra, as the god is also known beyond the Roman world, is a very ancient deity originally connected to Indo-Iranian groups, a branch of the Indo-European ethno-linguistic family. In written sources, the name of Mithra (written Mitra) appears as early as the 14th century BC, when the god is mentioned among other divinities of the Indo-Aryan pantheon in an alliance treaty sealed between the Hittite and Mitanni kingdoms. We find more detailed information about Mithra’s personality and functions in the sacred Vedic (Indian) and Zoroastrian (Iranian) texts that originated between the 2nd and 1st millennium BC: the Rigveda and the Avesta. The Avesta contains a hymn dedicated to Mithra, the ‘Mihr Yasht’, that paints the portrait of a solar deity, a god of justice who rules over alliances between gods and mortals and guarantees that contracts between people are upheld. This latter role finds a direct expression in the very name of ‘Mithra’, which is the ancient Persian word for ‘contract’. The description of Mithra (or Mihr) in the Avesta corresponds to observations made by ancient Greek authors such as Xenophon; according to him, the Persian kings of the Achaemenid dynasty used to swear by the god’s name.
During the Hellenistic period, there are signs of devotion to Mithra spreading west into Asia Minor. In a time marked by the cross-fertilisation of Iranian and Greek cultures, the god is frequently equated with various Hellenic counterparts. In the ancient kingdom of Commagene (modern eastern Turkey), he is referred to as ‘Apollo-Mithra-Helios-Hermes’, as attested by an inscription dated to the reign of King Antiochos I (1st century BC) found at the religious-monumental complex of Mount Nemrud (Nemrud Dagh). Likewise, one of the earliest pictorial representations of the god can be seen at the site: the beardless and juvenile face, as well as the eastern outfit (long tunic, loose trousers, and Phrygian cap), foreshadow the later depictions of Mithras in the Roman world.
Plutarch states that the Roman ‘mysteries’ of Mithras were first celebrated by Cilician pirates, who were deported from the south-eastern coast of modern Turkey to southern Italy in the 1st century BC, and so Asia Minor may be the region where Mithras first entered the Roman world. There is, however, no archaeological evidence to support this theory at present. And although some beliefs and concepts associated with Mithras were most likely borrowed from this eastern, Hellenistic region, they were evidently reformed and rearranged, shaping up a distinct occidental version of the cult. The emergence and successive diffusion of the cult of Mithras in the West is probably due to the movements of merchants, legionaries, and travellers of all stripes throughout the different regions of the empire.
Mithras is but one of the many foreign gods that were integrated into the Roman polytheistic belief system, together with Phrygian Cybele, Egyptian Isis and Serapis, and Greek Asclepius. Unlike these, however, Mithras never received official recognition and remained confined to the private sphere, where worship was left entirely to individual will and choice. The contractual nature of the mortal-divine relationship in Roman polytheism, which encouraged people to multiply their offerings to various gods, made it possible to worship in the same sacred space multiple divinities that shared similar functions. This expansive approach was also facilitated by Roman religion’s ability to adapt locally to existing native beliefs. The characterisation of Mithras as a ‘saviour’ deity probably accounts for his being worshipped next to local variants of Apollo and indigenous divinities that were endowed with healing powers and were generally connected to sacred springs. This link is especially evident in the eastern parts of Roman Gaul.
It was not until the end of the 19th century and the publication of work by the ‘father of Mithraic studies’, Franz Cumont, that an idea of the story of Mithras finally emerged. The Belgian researcher travelled tirelessly, from Syria to England, via Pontus and Armenia, in order to see the hundreds of images that allowed him to reconstruct a history of the god, filled with meaning and symbols, from his birth from a stone, to a regenerative sacrifice of a bull, and on to a dispute and then reconciliation with Sol, divine embodiment of the sun. The laconic and partial late-Christian written sources do not give enough information to complete Cumont’s ‘fabrication of the myth’. But one author, the 3rd-century AD philosopher Porphyry, in On the Cave of the Nymphs in the Odyssey, gave an astrological and eschatological interpretation of the cult, that strongly influenced the scholar. According to Porphyry, souls are impregnated with the effluvia of the seven planets before taking possession of bodies. The souls leave the bodies at death and go back up to the stars by crossing the seven planets again.
The images displayed in Mithraic sanctuaries provide a striking contrast to the typical Roman temple iconography. Usually, a temple contained a statue portraying the frontal view of the relevant god or goddess in a simple standing or seated position. The main recurring Mithraic cult image is, instead, the more dynamic tauroctony (killing of the bull). The composition seems to be unchanging: the god strikes the fatal blow to the animal, holding its leg with his foot, raising its head – usually by sticking his fingers into its nostrils – and piercing its right side with his knife. While a scorpion attacks the testicles of the sacrificed animal, a dog laps up the blood from its wound, and a snake bites its chest. A lion beside a krater is also sometimes included, these features symbolising the two elements of fire and water.
The classic bull-killing image has rightly been compared to the Nike Bouthutousa, in which Victory tames a bull. This was originally designed for the parapet of Athena Nike’s temple on the Acropolis in Athens. The design was later used on Augustan coins minted in Pergamon in 19-18 BC to commemorate the emperor’s victory in Armenia, the land of Mount Taurus. While we cannot be sure that the Classical Greek composition, or its Roman variation, is the direct source of the cult image of the tauroctony found in mithraea, it at least provides a close reference.
At any rate, the Roman prototype, that first Mithraic composition that became the source for the cult image reproduced in sanctuaries over the next three centuries, is assumed to have been conceived in Rome in the second half of the 1st century AD. The earliest known examples of the fixed cult image are statues dated from the end of the 1st century that were placed at the back of sanctuaries. Later on, the tauroctony image often takes the form of a relief or a painting. Scenes illustrating the main episodes of the story are added, as found at sites from Syria to the Rhine-Danube borders. As mentioned above, these are the scenes that enabled Franz Cumont to reconstruct the myth. In particular: Mithras being born from the stone; Mithras shooting an arrow towards a rock in order to make a spring flow, symbolising the regeneration of the earth; Mithras carrying the bull on his shoulders in order to sacrifice it in the lair; the fight against the jealous Sol and the handshake that seals the reconciliation between the two divine entities before the final banquet – the very same one that will be commemorated and reproduced by followers in all the sanctuaries.
Like the central image of Mithras found within, the Mithraic temple is, from a formal point of view, radically different from conventional Graeco-Roman sanctuaries. In place of the columns, pediment, and cella, it consists of a rectangular room, preferably with a vaulted ceiling, buried or half-buried, ideally even supported by a natural rock wall. In it are two benches facing each other and, at the end of the room, a niche or podium supporting the image of the cult: the Mithraic tauroctony in the form of a statue, relief, or painted figure.
The design of the mithraeum is most probably an allusion to two episodes of the myth and, by the same token, to their commemoration. Firstly, from a structural point of view, these temples evoke the cave in which the deity killed the bull. The rock had given birth to Mithras and it was in the heart of a stony space that Mithras subsequently spread the animal’s semen and blood, vital fluids bringing regeneration to the world. It is also inside this sacred architectural space that the adepts share the meal, probably the key event of the cult, in memory of the feast that united the two divine entities that rule the universe – Mithras and Sol.
Archaeological excavations of the sanctuaries and some rare texts shed light on the rituals. The presence of specific symbols – lion, krater, and snake – on cult objects and on sculpted reliefs suggests a link between the rituals and the mythological narrative.
Cult objects include incense burners, which are frequently found in mithraea. The use of smoke seems to have been a prerogative of one of the ranks associated with Mithraism, the leo (lion), whom an inscription from the sanctuary of Santa Prisca in Rome refers to as ‘incense burner’. The philosopher Porphyry mentioned the purifying symbolism of fire, which was replaced during ceremonies by ‘related lustrous liquids such as honey’. The Christian author Gregory of Nazianzus asserted (and Franz Cumont also assumed) that burns were actually inflicted on the followers; but this seems unlikely, as the biased Christian sources stigmatise the Mithraic ritual.
The mithraea have revealed traces of gutters and basins too, suggesting that water also played a role in the liturgy. The basins at the entrance to the cult hall and other vessels may have been used for purifying ablutions, a practice described by the Christian Tertullian in the early 3rd century as a ‘diabolical imitation’ of Christian baptism.
If worship of Mithras was left to individual choice in the private realm, who were his followers? The small communities who worshipped him, although not clandestine, were not necessarily officially recognised by local authorities, and how the cult was run remains poorly understood. Without a centralised authority, each community organised itself in its own way and financed the cult and the maintenance of the sanctuary where its members worshipped together. These groups of modest size were characterised by the strong bond that united their members, as reflected in the inscriptions: the followers sometimes present themselves as cultores Mithrae (followers of Mithras), syndexoi (united by the handshake), or even as fratres (brothers).
The cult of Mithras recruited followers from both civilian and military circles, citizens as well as slaves and freedmen. Mithraic communities usually appeared in professional settings: some mithraea brought together soldiers belonging to the same legion or employees of the same administrative office, such as the ‘custom office’ of Pannonia. A significant number of sanctuaries were established in the annexes or storage rooms of public buildings, as well as next to areas dedicated to a trade or craft. Others were built in rural areas.
Women are absent from Mithraic inscriptions, but this does not necessarily mean that they were forbidden access to the cult. The social or professional networks through which the communities were formed may simply have contributed to attracting a majority of men. It is also possible that women may have performed specific functions that are not reflected in the epigraphy.
The internal organisation of at least some Mithraic communities appears to have been structured in grades, including the incense-burning leo. At the beginning of the 5th century, Saint Jerome lists seven such grades, which can be linked to the symbols illustrating the mosaic of the mithraeum of Felicissimus in Ostia, outside of Rome. Three of them – the corax (raven), the leo, and the pater (father) – appear quite regularly in the inscriptions and seem to designate the new initiates, the confirmed members, and the leaders of the communities respectively. The other four grades, which are almost never mentioned in the archaeological evidence, could have emerged later in the history of the cult. Regardless of their number, it remains uncertain whether these ranks were accessible through a progressive initiation or whether they simply designated distinct liturgical functions or levels of responsibility within the group.
In antiquity, the term ‘mystery’ was used to emphasise the secret dimension of certain cults involving an initiation that conferred philosophical knowledge and allowed for spiritual transformation. Franz Cumont saw in these mystery cults a prefiguration of the Christian themes of revelation and salvation of the soul. This view is now being questioned. In the mithraeum of Santa Prisca (Rome), certain graffiti could well evoke the symbolic rebirth and moral progression that initiation allowed. These themes are also evident in the philosopher Porphyry’s writings, but we do not know if all groups of followers shared these beliefs.
Gregory of Nazianzus and Ambrosiaster, two Christian authors of late antiquity, describe initiation as brutal: they mention ‘punishments’, or describe initiates who, blindfolded and with their hands tied, are thrown into pools of ice-cold water. Tertullian speaks of rituals using crowns and swords. Such objects have been discovered during archaeological excavations and may have been used during initiation rituals, though we should refrain from a literal interpretation of Tertullian’s text. Christian authors are biased, of course, and generally very critical of all non-Christian cults and rites. Although exaggerated in these accounts, the purported violent practices of Mithraic rituals could correspond to symbolic gestures, re-enactments of specific episodes of the myth.
Even during the period of full expansion of the cult, in the 3rd century, natural disasters or the weakening of the architectural structures led to the destruction of some sanctuaries; for example, mithraeum II at Güglingen and the mithraea of Künzing and Virunum.For reasons that remain unclear, they were never restored. Internal crises within groups of followers, impoverishment of certain communities, displacement to more dynamic living areas, or simple disinterest in the deity may all have played a part.
Along the border in Upper Germania, it was a backlash against the Roman army as early as the 3rd century that could explain the desecration and destruction of several mithraea. From that point on, these temples were no longer protected. Archaeological research allows us to connect certain violent events to peoples beyond the borders. Moreover, in these frontier zones, there was a link between, on the one hand, the weakening and endangerment of the temples and, on the other hand, the partial or total abandonment of many towns and secondary settlements (vici). Decapitation of the sculptures, a sort of ritual ‘killing’, heralded what was to come in the following century; for example, at the site of Angers in western France. In the frontier regions, where Mithras remained strongly associated with the Roman army, breaking the divine images undoubtedly represented a highly symbolic act of war.
In the 4th century there was a sharp and rapid decline in the construction, as well as the upkeep and continued use, of sanctuaries dedicated to Mithras. In addition, the occasional destruction of temples by Christian iconoclasts became a reality, especially after the Edict of Thessalonica promulgated by Theodosius in 380, which recognised Christianity as the only official religion of the Roman Empire. Throughout the land, mithraea were abandoned under pressure from the Roman soldiers or the imperial administration.
As temples fell into disuse and disrepair, some cult images remained in place, while others were moved and reused at other active sanctuaries. Some were even stored and exhibited in private homes. The tauroctony from Cabra (in southern Spain), for example, which introduces and closes the exhibition, is a marble group placed in the niche of a pleasure pool in a villa restructured in the 3rd century. Such an object crystallises the typical fate of ancient works in late antiquity, where ornamental function and memorial value were combined. And though the private nature of his cult means that there is much that remains mysterious about Mithras, it is through such imagery that the Roman iteration of the god is perhaps best remembered today.
The Mystery of Mithras: exploring the heart of a Roman cult runs at the Musée Saint-Raymond in Toulouse until 30 October. See www.saintraymond.toulouse.fr for details.
The next exhibition will be held at the Archäologisches Museum Frankfurt between 24 November and 9 April 2023 (www.archaeologisches-museum-frankfurt.de).
The scientific catalogue is edited by Laurent Bricault (Toulouse II – Jean-Jaurès University) and Richard Veymiers (Royal Museum of Mariemont). It includes contributions from distinguished specialists on the cult of Mithras and brings together the full selection of works featured in the three iterations of the exhibition in Belgium, France, and Germany.