Definition: Mithraism
Religion based on devotion and worship to Mithra, the Iranian god of the sun, justice, contract, mediation, and war in pre-Zoroastrian Iran.

Mithraism is a Roman mystery religion that flourished in the 2nd through 4th centuries CE. Much is still unknown about this secretive sect, but it involved the worship of the Persian god Mithras in caves, a communal meal, and initiation through seven stages of an astrologically-themed hierarchy. It seems to have been for men only and was especially popular among soldiers.

Evidence and Sources

Mithraism is known almost entirely from physical artifacts and dedicatory inscriptions. In total, over 400 archaeological find-spots related to Mithraism have been uncovered, along with about 1,000 dedicatory inscriptions and 1,150 pieces of sculpture.

There are very few contemporary written sources, and most of them are outsider perspectives. References to Mithraism can be found in the following texts:

  • Plutarch, Life of Pompey 24
  • Porphyry, On the Cave of the Nymphs 6, 15-16, 17-18, 24-25
  • Porphyry, On Abstinence from Animal Foods 4.16
  • Tertullian (c.200), On the Soldier's Crown 15
  • Origen (240s), Against Celsus 6.22

The lack of good written sources on Mithraism is largely due to its status as a mystery religion, in which the meaning of its iconography and rituals was a secret known only to initiates. Insiders did not record details of their religion and outsiders did not know much about it. This obviously makes things difficult for historians, so there is much about Mithraism that is still not known.


The origins of Mithraism as a Roman cult are not fully understood. It clearly derives from ancient Persia in some way, but scholars are divided on whether the Roman cult is a westernized Persian religion or an essentially western religion with Persian trimmings.

The time period in which Mithraism flourished is better known, thanks to the archaeological evidence. The cult of Mithras appears suddenly in the 2nd century CE: hundreds of inscriptions begin appearing after 136. It then died out with the rest of Greco-Roman paganism after the conversion of Constantine in the 4th century.

Mithraism's sudden emergence in the Roman world has not been explained. According to the Encyclopaedia Britannica,

The most plausible hypothesis seems to be that Roman Mithraism was practically a new creation, wrought by a religious genius who may have lived as late as c. 100 CE and who gave the old traditional Persian ceremonies a new Platonic interpretation that enabled Mithraism to become acceptable to the Roman world.[#784]

Archaeological finds indicate the extent of Mithraism included most of the Roman Empire, from Rome to Turkey to Britain. It was especially concentrated in Rome (35 Mithraic temples found) and its port of Ostia (15 temples).

The cult was supported by several emperors, including Commodus (180-92), Septimius Severus (193-211), and Caracalla (211-17). As part of an effort at renewing the Roman empire, Diocletian dedicated an altar to Mithras in Carnuntum (on the Danube near Vienna) in 307, designating the god "patron of the empire" (fautori imperii sui).

Most followers of Mithraism were Roman soldiers, minor government employees like customs officials, imperial freedmen, or slaves. It was also adopted by the pagan aristocracy of 4th-century Rome, as part of a conservative movement in opposition to the new Christian empire based in Constantinople.

Mithraism and Christianity

Mithraism is frequently said to have been a great rival to early Christianity, especially in popular books written by non-specialists. According to most academic sources, however, the archaeological evidence does not support this claim.

Although it was widespread in terms of geography, Mithraism never had great numbers. (Christianity was not terribly large or influential in this period, either.) A few hundred temples of Mithras have been discovered across the Roman empire, but they are all very small. According to the Oxford Dictionary of Classical Myth and Religion:

Even if all were in service contemporaneously they would accommodate no more than 1 percent of the population - scarcely the great rival to Christianity that inflated views of the cult have sometimes made it.[#783]

Whether or not they were rivals, it is certainly possible that these two contemporary communities had some influence on each other. In at least one area, it is clear that Christianity adopted an aspect of Mithraism - the celebration of the birth of Christ on December 25, a tradition that began in the 4th century. A Christian writer admitted this in 320, explaining:

We hold this day holy, not like the pagans because of the birth of the sun, but because of him who made it.[#789]

December 25 was also the birthday of the more popular Roman god known as the "Unconquered Sun" (sol invictus) who was closely associated with Mithras. Emperor Constantine identified himself with this sun god before his conversion to Christianity.

In considering claims for Mithraism's influence on Christianity, it is important to remember that Mithraism was a very secretive, initiatory cult whose beliefs, practices and imagery were not known to the outside world. So it would not have been as easy for Christianity to borrow ideas from it as one might assume.

It is also worth noting that two faiths developing in the same area of the world at the same time are likely to have similar ideas and practices, regardless of their level of interaction. Ritual communal meals and the theme of sacrifice for salvation, for instance, were common not only to Mithraism and Christianity but much of the ancient world.

Beliefs and Iconography

Because of the lack of written sources, little is known about the beliefs of Mithraism. But they clearly centered on the god Mithras, who was based on the pre-Zoroastrian Persian god Mithra. Mithra was the most important god in Persian polytheism.


The Persian Mithras was a god of contracts (which is the literal meaning of his name) and all things associated with contracts: justice, friendship, cattle-herding and the sun (which beholds all things and thus can ensure the keeping of oaths). Zoroaster (6th century BC) specifically denounced the sacrifice of the bull, suggesting this was a ceremony of the ancient worshippers of Mithras.

In a Roman context, Mithras was the invincible sun god (sol invictus), a "bull-slayer," "cattle-thief" and the savior of initiates of his cult. He was probably also the god of kings and of war, which would explain the religion's popularity among soldiers.

Mithras Slaying the Bull

The image of Mithras killing a bull is central to nearly all Mithraic temples, and thus provides an important (but difficult) clue to the beliefs and concepts of Mithraism. Mithras is shown dressed like a Persian, including a distinctive cap. He stands astride a bull, plunging a dagger into its flank. The bull's tail becomes an ear of wheat at the end. The scene takes place in front of a cave.

Mithras is shown accompanied by a dog, snake, scorpion and raven, as well as two minor deities who are also dressed in Persian attire. Each carries a torch (one pointed up, one down) and their names are known from inscriptions: Cautes and Cautopates. Above the scene are images of Sol and Luna (Sun and Moon).

This intriguing iconography continues to fascinate and frustrate scholars. The act clearly represents a sacrifice, but for what purpose? Scholars have suggested that the sacrifice creates or ends the world (an idea found in Zoroastrian sources) or somehow saves the world or the initiates of the cult. In a Mithraic temple in Rome, an inscription reads et nos servasti... sanguine fuso: "and who saved us with the shed blood." If this is the meaning of the bull-slaying image, it still remains unclear what "salvation" meant to followers of Mithras.

Another interpretation of the bull-killing scene is that it is an astrological allegory, since elements in the scene correspond to a group of constellations. According to this view, astrology was central to Mithraism and it provided the specifics of the soul's celestial journey (descent to earth and ascent to heaven).

The Banquet and Other Scenes

Besides this central icon, there are other episodes of Mithraic myth depicted as well. These include Mithras' birth from a rock, the hunt and capture of the bull, and a banquet celebrated with Sol (who is shown as a separate being on monuments despite Mithras' own designation as a sun god). The divine meal is laid on the hide of the bull killed by Mithras. The banquet scene is sometimes shown on the reverse of the bull-killing reliefs, as an apparent result of the sacrificial act.


Followers of Mithraism were organized into small autonomous groups of initiates. As in its Persian form, Roman Mithraism was a religion of loyalty, contracts and friendship between men, especially between officials and rulers. There are no known women followers of Mithraism.

It is probable that each Mithraic temple and community was presided over by one or more Fathers. But the initiates of Mithraism, even in the highest ranks, were not professional priests. Their monuments attest that they remained active members of the secular world.

Mithraic Temples

Initiates met for fellowship and worship in small temples of distinctive design they simply called "caves." ("Mithraea" and "Mithraic" are modern terms.) The cave-temple was an "image of the universe" and Porphyry noted that the archetypal Mithraeum was designed as a kind of microcosmic model.

Mithraic temples were sometimes actual caves or set against rock faces; otherwise they were made to imitate caves by the use of dim underground rooms or special vaulting and decoration. They were in all cases the antithesis of the classical temple, entirely lacking in exterior decoration and grandeur for public ritual.

Ritual Meal

One unvarying feature of Mithraic temples is a pair of platforms flanking a central aisle. These furnishings were used for a communal meal. Based on the reliefs that show a feast between Mithras and the sun god, this ritual meal was the human counterpart of the divine banquet.

Initiation Ceremonies

Another central ritual was initiation into seven successive levels. Contemporary sources indicate this included ablutions (or baptism), purifications, chastisements, fetters and liberation, and ceremonial passwords. Frescoes at Capua (Italy) show the initiates blindfolded and kneeling.

A simulated death and resurrection was probably part of the ceremony, as the ascent through the initiation grades was seen as prefiguring the ascent of the soul after death.

Seven Grades of Mithraism

Mithraic initiates were ranked in a series of seven grades, each named and each under the protection of one of the planets:

  1. Raven (Mercury)
  2. Nymphus (Venus)
  3. Soldier (Mars)
  4. Lion (Jupiter)
  5. Persian (Moon)
  6. Heliodromus (Sun)
  7. Father (Saturn)

These initiatory grades are known from frescoes in the Santa Prisca Mithraeum in Rome and the mosaic pavement of the Felicissimus Mithraeum in Ostia. But "Nymphus" (which translates to "male bride" or "bridegroom") and "Heliodromus" are words of unclear meaning, and all the grades remain full of mystery.

The Christian author Tertullian sheds some light on initiation to the third level, "Soldier," in a treatise about Christians refusing crowns in military service (On the Soldier's Crown 15). He notes that a Soldier of Mithras, during his initiation in some gloomy cave, is presented with a crown at sword-point. He refuses it, saying that Mithras is his crown, and he never wears a crown after that.