What Is Mithraism? The Secretive Cult That Swept the Roman World

Mithraism was an enigmatic cult religion that flourished in the Roman Empire between the 1st and 4th centuries CE. Highly secretive by nature, historical understanding is challenged by the minimal record we have inherited about this fascinating cult. References are scant, anecdotal, and often biased by religious prejudice. Archaeology has expanded our view of Mithraism, though it is subject to interpretations and debate. Just what Mithraism was — its origins, practices, and impact — are all open to interpretation.

Of ancient Indo-Iranian origin, Mithraism was centered in present-day Iran, the epicenter of the Persian Empire. Significantly predating Western historiography, Zoroastrian Mithras was first recorded (in the West) by early Greeks such as Herodotus and Xenophon.

A cosmic power, the eastern Mithras ascended to the heavens overseeing the order of the universe. Associated with fire and the sun this powerful deity kept harmony in the cosmos and in the world of men.

A culturally interwoven figure, Mithras evolved via an infusion of Zoroastrian and Vedic interpretations existing long before its Greco-Roman exposure. Variants of Mithras (Mehr, Myhir, Mihr, Mitra) existed among Persian, Assyrian, Arabian, Armenian, Bactrian, and other peoples and predated Rome’s ascendancy in the East by more than a millennium. There is no knowing how confused Mithraic iterations had become by the time Rome encountered the god.

Roman Mithras, was a singularly male god, associated with the sun and the heavens. Complete with a Phrygian cap, trousers, and cape, his depiction is felt by some historians to be almost a cliché of Easternism. Seen in Roman mosaics, carvings, and freezes, Mithras manifested all over the Roman empire from the later 1st century CE.

The Bull Slayer

Roman Mithras is commonly portrayed ritually sacrificing a bull. Known as the “tauroctony,” this iconography is common to Mithraic sites, shown in carvings, wall freezes, and mosaics with great consistency. Regional variations do occur, though core scenes always depict Mithras in his Phrygian cap and Anatolian trousers, sacrificing a great bull. Often in a cave, common features include a dog and a snake that sup at the sacrificial wound. A scorpion is present nipping at the bull’s testicles, with a raven usually looking over the scene.

A sheaf of corn is ritually tied to the bull’s tail, as two torch bearers commonly surround the killing. The torchbearer Cautes holds a torch aloft and while another torchbearer Cautopates holds a torch inverted. Outside the cave, we see the sun (Sol) and a corresponding moon. Other additions can relay the birth and life of Mithras, though these vary.

Significant symbolism has seen many interpretations with some focusing on zodiac references. Theories are hotly contested, and we simply do not know their definitive meanings. However, we might guess at some likely themes around birth, life, death, sacrifice, fertility, harvests, seasons, day, night, and the celestial cosmos.

Other Mithraic depictions show the god’s mythical life story and include images of hunting, dragging, and riding the great bull. Mithras can hold a torch or bow. In some instances, he uses the bow to hunt or fire into nearby rocks, from which water gushes.

Representations of Mithras being born of a rock, reinforce that there was no place for women within the cult, even in motherhood.

“Mithras desirous to have a son, yet hating womankind, lay with a stone, till he had heated it to that degree that the stone grew big, and at the prefixed time was delivered of a son,;…”
[Pseudo Plutarch, De Fluviis, XXII, Araxes]

Indeed, the absence of any female engagement in either literary or epigraphic sources is conspicuous, with a strong feeling that the cult may have been misogynistic.

The locus of Mithraic iconography is to be found largely in subterranean temples, dedicated to the god. Roman Mithraea show up all over the empire from the 1st to 4th centuries CE. Spanning from Northern Britain to the heart of Rome and distant North Africa, temples attest to the significant popularity of Mithraism.

At both significant and remote sites, temples, although found in all parts of the Empire, are not evenly distributed. There is a relatively dense profusion in central Italy, Numidia, Dalmatia, Germania, and Britain, which has led some historians to ask just how Mithraism spread. Though found in all parts of the empire, Mithraic distribution is relatively under-represented in Greece, Egypt, Asia Minor, and Syria — strange for a religion that came from the East.

Small and secretive subterranean Mithraea are often found in scores across individual cities, including Rome, and attest that sect-like groups practiced the religion and its secret rites. Ostia, Rome’s major port, can attest to more than 15 such temples alone.

Long, narrow, and dark, Mithraea were small with little grandeur. Usually elongated subterranean chambers with no windows, they include an antechamber and main room. Fashioned from caves, or carved out of basements, they were often built near sources of running water, which is thought to have been integral to the practice of some rites. Basins or fonts are also found in many examples.

The central focus of all the Mithraea was a stone altar or freeze that often depicted an image of the god ritually sacrificing a bull. These dark spaces mirrored the highly secretive nature of the cult and represented a physical cave; a symbolic representation essential in the Mithraic story. Most elements of Mithraic iconography are constant, though regional variations are evident, suggesting this was an organic and somewhat localized religion.

Despite the secrecy surrounding Roman Mithras, it is possible to piece together some of the ancient cult’s practices, from various observations and commentary. However, some branches of pagan philosophy and certainly Christianity were deeply hostile to Mithraism. Initiation rites are hinted at in various sources, though we have little idea if these accounts are wild or accurate.

Open only to men, the cult debarred the participation of women and presented as highly hierarchical. Members were referred to as syndexioi, or “those united by the handshake.” Archeological evidence suggests that feasting rituals were a distinctive part of the cult’s subterranean practices.

Inductees progressed through grades of initiation with seven ranks referenced including “ravens,” “fathers,” “bridegrooms,” “soldiers,” “lions,” “Persians,” and “sun-runners.” Each rank carried different duties and rites conducted to strict and symbolically significant patterns.

“Some like birds flap their wings imitating the raven’s cry; others roar like lions; others bind their hands with the entrails of fowls and fling themselves down over pits full of water, and then another whom they call the Liberator approaches with a sword and severs the above-mentioned bonds.”
[Pseudo Ambrose, Quaestiones veteris et novi testamenti 114.11 (PL 35, col.2343)]

At the Mithraeum of Santa Maria Capua Vetere, several wall freezes depict initiation rites that seem to involve discomfort, endurance, or humiliation. Other sources mention discomfort within initiation, like being blindfolded, bound, or doused in water. The infamous Emperor Commodus in the late second century CE was himself a practitioner of the cult and is accused of taking things too far:

“He desecrated the rites of Mithra​ with actual murder, although it was customary in them merely to say or pretend something that would produce an impression of terror.”
[Historia Augusta 9]

It’s hard to know if the details are accurate, or just the shock accusations of those on the outside describing something they did not like, trust, or understand.

Establishment in the West

Just how Mithraism spread throughout the empire is a further mystery. Worship may not have traveled at all and there are some historians who believe that Roman Mithraism may even have been constructed in the Roman West, although evidence is patchy.

If it did travel, then a rare possibility comes to us from the biographer Plutarch, who says it was accelerated by the great Pirate blight of the mid-1st century BCE:

“[Cilician pirates] attacked and plundered places of refuge and sanctuaries hitherto inviolate, … They also offered strange sacrifices of their own at Olympus, and celebrated there certain secret rites, among which those of Mithras continue to the present time, having been first instituted by them.”
[Plutarch, Life of Pompey 24]

Pirates or not, a seaborne diffusion of the Mithraic religion is plausible and there are those that argue that the diffusion of mithraea could in part be interpreted as mapping onto major ports and trade routes. Could traders have transposed the religion throughout the empire? It is more than possible that Mithraism spread via trade and its linkages with the army would also not preclude this. This might also account for major trade centers such as Ostia, having such high concentrations of Mithraea, and might explain why they are not found evenly throughout the empire.

A clearly important mechanism for Mithraic diffusion was the Roman army. From across the empire archeological siting of Mithraea and inscriptions, suggest that Rome’s military closely identified with the secret mystery cult. With its all-male composition and secretive and hierarchical structure, the cult seems to have appealed to soldiers — though it is important to note that its appeal was broader than just the army.

Found not only at major legionary sites, Roman Mithraea are also present at far-flung camps all over the empire. In the East, we have a rare but highly significant example at the site of a castra at Zerzevan, (in modern-day Turkey), a site used by Roman garrisons in the 3rd century CE. Zerzevan hosts an impressive Mithraeum. One of the very few Roman military Mithraeums found along the Eastern borders, it is a strange anomaly for a supposedly “Eastern” religion.

There are also numerous military examples of Mithraea found along the militarized northern Britain, Rhine, and Danube frontiers, as well as North Africa. The military camps along the formidable Hadrian’s Wall are reflective of the local context in which the cult could operate. A Mithraeum found at the major infantry fortress of Housteads, for example, is significant. But so too are cohort-sized castra such as Brocolitia (modern Carrawburgh). Active as a temple between c. 200 CE to 350 CE, Carrawburgh’s Mithraeum yielded three alters that included various dedications by the commanding officers of the First Cohort of Batavians from the Rhineland.

Excavations at the much larger camp of Housteads also reveal a carving of Mithras unique in the archaeological record. Here there is a stone carving of Mithras being born of an egg, rather than sprouting from stone, as he commonly does. Surrounded by signs of the zodiac, this unique egg-born Mithras is thought to have become fused with the god Phanes who was a Greco-Asiatic symbol of fertility and regeneration from the Orphic tradition. Reinforcing this anomaly are dedications to a variant of Mithras, “Mithras Saecularis” or Mithras, “Lord of his Age.”

Historians increasingly equate this and other variations (from all over the empire) with the notion that Mithraism was subject to regional interpretations and was to some degree “localized.”

We might assume that Mithraism was accepted by the Roman state, especially with its seemingly important links with the army, and association with at least some emperors. However, we simply do not have much detail and it may be that the cults “secret” nature, (even as an ill-kept secret) allowed for the state to turn a blind eye.

Mystery cults were ten-a-penny in the ancient world, both in the Roman world and in the Hellenistic, Egyptian, and Persian East. Many domestic and foreign examples predated the arrival of Roman Mithras and had a mixed reception in the capital.

Roman polytheism accepted and co-opted many religions into its diverse pantheon and was indeed a part of the Roman foundation. Rome as a culture borrowed gods via Etruscan and Greek influences.

Syncretism was also a useful tool and part of Rome’s deliberate cultural assimilation of other peoples, as it grew and strengthened its empire. Within this definition, Rome can be seen as religiously liberal and surprisingly tolerant. However, acceptance and integration of foreign religions could never be taken for granted.

Rome (the cultural mixing pot of the empire) also had a long history of religious persecution; especially of foreign religions and cults that challenged core Roman ideals and notions of “Roman-ness.” Where foreign stems could be grafted onto strong Greco-Roman branches without trauma or challenge to authority, they often were, but such assimilation could never be taken for granted.

Religious Persecutions 

Where beliefs collided with Roman virtues and challenged traditional authority, they were ruthlessly persecuted. Many focus on the various persecutions of Christianity between the 1st and early 4th centuries CE but it was only one of several suppressed religions in Rome.

Wild and secretive Greco-Italian Bacchic rites were suppressed as early as the 2nd century BCE. Though not domestic, Rome’s violent reaction to Celtic Druidic belief was also notably violent.

Maligned Egyptian cults were banished from Rome in the 1st century CE by the cultural conservative Augustus. Claudius was the first to expel Jews from Rome, and Nero took up Christian persecution with relish. In the 3rd Century CE, Manichaeism from the Parthian East was also suppressed under an imperial edict of Diocletian — an emperor who ruthlessly suppressed Christianity. Just why Mithras, who also had strong Parthian associations, was left alone, is a true enigma.

Distasteful “foreign” religions (especially secret ones) made for conspicuous targets. This was primarily about asserting Roman control and Roman ideals. Moral panic frequently accompanied persecution as Rome sought to preserve its own culture. The children of Romulus did not conquer the known world, just to “turn native.” A strong and conscious resistance to foreignness persisted especially in the Republic and well past the early Principate.

Yet, for an empire flourishing on the sweat and blood of foreigners, the inevitable influence of diverse cultures could not be resisted. Assimilation is always a two-way street, even when grossly unequal. Rome was the great conveyor, bringing millions of people forcibly into the heart of the Empire. Intentional or not, this included their gods. Administrative mechanisms of conveyance, like the army, governors, colonialists, traders, private businesses, and tax collectors, all increased the potential for religious diffusion.

As the empire deepened its integration with the East, it was inevitable that foreign and exotic religions would enter the Roman cultural orbit. Many of these new religions were already reassuringly Hellenized, yet others held stranger and more foreign concepts or beliefs.

Discerning Rome’s point of comfort and religious tolerance was never simple, not least because tolerance shifted as Rome matured into a more multiethnic, if not a more multicultural, empire. Though some religious phobia diminished, it is amazing that Mithraism seems to have been well tolerated, when other foreign sects were not.

By the 4th century CE another Eastern religion, Christianity, would start to dominate the Roman world. It was radically intolerant of pagan belief, creating tensions with the old gods, and heightening them over many decades if not centuries. Rome’s new Christian religion spelled the death knell of Mithraism and all other pagan cults. Late Roman Christian writers could not hide the affront that Mithras and his followers presented to their faith.

“They say (this god) is Mithras, but they perform his initiations in caves that are hidden away, so that, plunged perpetually into the pitchy murk of night, they may shun the grace of the bright and glorious light. …”
[Julius Firmicus Maternus  De Errore profanis religionis, ch. 4]

Literary and archeological records show that active persecution of pagan cults took place with considerable zeal into the 4th and 5th centuries CE. Archeology from various sites such as Ostia shows signs of deliberate Christian spoilation where Mithraic iconography was ritually smashed and buried below the sites of later Christian churches. Mithraism was certainly dying out, and its departure from the archaeological record was rapid within the last age of Rome.

Enigmatic, strange, and fundamentally “foreign,” there is far more that we do not understand about this cult than we do. That Mithras was imported, borrowed, or culturally interpreted from the East, seems likely, though just how authentic or how constructed it was from those roots is unknown. Why it flourished in the later Roman empire, is an enduring conundrum. Evidently popular, what Mithraism offered Romans, we may never understand.

Evidently, Mithraism wielded considerable power in the Roman state, though that influence was likely to have been clandestine. Links with the Roman army were strong, though others like freedmen, traders, and imperial administrators, right up to emperors were practitioners or patrons.

History will continue to theorize about Roman Mithras. Yet, in the final analysis, there has only ever been one rule about secret mystery cults: you don’t talk about secret mystery cults. This is the reason we know so little about Mithras.