It is surmised that the Mithraists worshipped Mithras, as the supreme God of the upper and nether world. Their beliefs apparently included that their god died, was buried in a rock tomb, and was resurrected. The Mithraic god is depicted as a man. This man is also shown as being born or rising from a rock (typically with a snake wrapped around it). Some speculation includes that this rock symbolizes the outside of the cave of the cosmos, hence the description of this god as 'rising from the dead'. Other depictions show Mithras carrying a rock on his back, much as Atlas did, and showing him wearing a cape that had the starry sky along its inside lining.
The earliest evidence to which a date may be assigned for the worship of Mithras is the late 1st century A.D. . This is from a record of Roman soldiers who came from the military garrison at Carnuntum near the Danube River in the modern area of Hungary (the Roman province of Upper Pannonia). These soldiers fought against the Parthians and were involved in the suppression of the Jewish people who revolted in Jerusalem from 60 A.D. to about 70 A.D. . When they returned home, they made mithraic dedications. (proabably in the year 71 or 72 A.D.)
Soldiers appeared to be the most plentiful followers of Mithraism, but women were apparently not allowed to join.
Concentrations of Mithraic temples are found on the outskirts of the Roman empire, ie: along Hadrian's wall of England, along the Danube and Rhine river frontier, in province Dacia (in 2003 a temple was found in Alba-Iulia) and as far as Numidia in North Africa. As would be expected of this theory, Mithraic ruins are also found in the port city of Ostia, and Rome the capital, where as many as seven hundred mithraea apparently existed. Recent excavations in London have uncovered the remains of a Mithraic temple near to the center of the once walled Roman settlement, on the bank of the Walbrook stream.
Franz Cumont, a Belgian historian of some note in the 1800s, proposed that Mithraism came originally from Iran. While there is an Persian deity named Mithra, there is no known legend about that deity killing a bull with the assorted other animals, nor is there any known text detailing such a story. However, there is a story of Ahriman, the evil god in one persian religion, killing a bull.
Cumont's student, Maarten J. Vermaseren, was very active in translating mithraic inscriptions.
An alternate interpretation of the common picture is that it is a picture of the great cave of the sky. This interpretation was supported by research by K. B. Stark in 1869, with astronomical support by Roger Beck (1984 and 1988), David Ulansey (1989) and Noel Swerdlow (1991). This interpretation is reinforced by other common images in mithraeum of heavenly objects, such as stars, the moon, and the sun. It has been suggested that that the Mithraic religion came into existence when the 'age of Taurus' as the equinox precessed into the 'age of Aries' at about the year 2000 B.C. Mithras was presumed to be very powerful if he was able to rotate the heavens, and thus 'killing the bull' or displacing Taurus as the reigning image in the heavens.
This 'age of Sign' nomenclature is based on the astronomical sign present during the spring equinox of that age, as generally viewed in the Mediterranean region of the Northern Hemisphere. Taurus the Bull was prominent before as spring equinox, culminating with Scorpio as the autumn equinox. This change of age occurs approximately every 2,160 years. The current age started when the equinox precessed into the 'age of Pisces', at about the year 1 AD, with the 'age of Aquarius' starting within the next few centuries.
Supporting this theory of the details of Mithraic belief is the addition of a lion and a cup in some depictions of the tauroctony. Leo (a lion) and Aquarius (the cup-bearer) were the constellations seen as the northernmost (summer solstice) and southernmost (winter solstice) positions in the sky during the 'age of Taurus'.
Historical evidence supporting this view is scanty, as is mention of Mithraism itself. The Greek astronomer Hipparchus discovered and publicized the equinoctal precession. Whether it was known by Mithraists previously is unknown. The writer Porphyry recorded that the cave pictured in the tauroctony was intended to be "an image of the cosmos." The writer Plutarch wrote about pirates of Cilicia who practiced the Mithraic "secret rites" in the first century BC (about 67 B.C.). Since Cilicia was the name of an area near Turkey and Greece, the Mithras mentioned by Plutarch may have been worship of the Persian god Mithras, or may have been associated with this god who killed a bull.
The members of a Mithraeum were divided into seven ranks. All members were apparently expected to progress through the first four ranks, while only a few would go on to the three higher ranks. The first four ranks seem to represent spiritual progress, while the other three appear to have been specialized offices. The seven ranks were:
An English monument found near mithraic ruins, and an inscription from the city of Rome suggest that Mithras may have been seen as the Orphic creator-god Phanes who emerged from the cosmic egg at the beginning of time, bringing the universe into existence. A bas-relief in Modena Italy at the Galerie e Museo Estense, shows Phanes coming from an egg, surrounded by the twelve signs of the zodiac, in an image very similar to those found in some mithraeum. Phanes in Greek means 'manifestor', or 'revealer', and he is also called Love (Eros), and First-born (Protogonos).
There is some speculation that Mithraic belief was influenced by Christian beliefs, or vice-versa. Ernst Renan promoted the idea that Mithraism was the prime competitor to Christianity in the second through the fourth century, although most scholars feel the written claims that the emperors Nero, Commodus, Septimius Severus, Caracalla, and the Tetrarchs are dubious at best, and there is no evidence that Mithraic worship was accorded any official status as a Roman cult.
There is some evidence that the Orobouros (snake wrapped about to bite its own tail) was an early Christian symbol of the limited confines of time and space. The snake around a rock also is reminscent of the Midgard serpent Jormungand who was said to surround Midgard (the Earth) according to Norse traditions.
The First International Congress of Mithraic Studies was held in 1971 at Manchester England.