Mithraism
Mithraism, also known as the Mithraic mysteries or the Cult of Mithras, was a Roman mystery religion centered on the god Mithras. Although inspired by Iranian worship of the Zoroastrian divinity (yazata) Mithra, the Roman Mithras was linked to a new and distinctive imagery, and the level of continuity between Persian and Greco-Roman practice remains debatable. The mysteries were popular among the Imperial Roman army from the 1st to the 4th century CE.
Worshippers of Mithras had a complex system of seven grades of initiation and communal ritual meals. Initiates called themselves syndexioi, those "united by the handshake". They met in dedicated mithraeum (plural mithraea), underground temples that survive in large numbers. The cult appears to have had its center in Rome, and was popular throughout the western half of the empire, as far south as Roman Africa and Numidia, as far east as Roman Dacia, as far north as Roman Britain,(pp 26–27) and to a lesser extent in Roman Syria in the east.
Mithraism is viewed as a rival of early Christianity.(p 147) In the 4th century, Mithraists faced persecution from Christians, and the religion was subsequently suppressed and eliminated in the Roman Empire by the end of the century.
Numerous archaeological finds, including meeting places, monuments, and artifacts, have contributed to modern knowledge about Mithraism throughout the Roman Empire. The iconic scenes of Mithras show him being born from a rock, slaughtering a bull, and sharing a banquet with the god Sol (the Sun). About 420 sites have yielded materials related to the cult. Among the items found are about 1000 inscriptions, 700 examples of the bull-killing scene (tauroctony), and about 400 other monuments.(p xxi) It has been estimated that there would have been at least 680 mithraea in the city of Rome. No written narratives or theology from the religion survive; limited information can be derived from the inscriptions and brief or passing references in Greek and Latin literature. Interpretation of the physical evidence remains problematic and contested.