Mithra

Mithra in Zoroastrianism is a yazata of covenant, light, and oath who judges souls after death, while Roman Mithraism was a mystery cult that emerged in the Roman Empire around the 1st century CE. The Roman cult adapted the Indo-Iranian deity but developed entirely distinct rituals and theology, most notably the tauroctony scene depicting Mithras slaying a bull, which has no parallel in Zoroastrian tradition.

The Roman cult of Mithras spread widely across the empire by the 2nd century CE and peaked in the 3rd century before declining with the rise of Christianity. Mithraea, the cult's underground temples, have been found from Hadrian's Wall in Britain to Dura-Europos in Syria. The cult was especially popular among Roman soldiers and merchants.

Roman Mithraism featured seven grades of initiation: Corax (Raven), Nymphus (Bridegroom), Miles (Soldier), Leo (Lion), Perses (Persian), Heliodromus (Sun-Runner), and Pater (Father). Each grade was associated with a celestial body and a tutelary deity. The cult was exclusively male, and initiations involved ritual meals and symbolic tests of endurance.

Over 200 Mithraea have been identified across the former Roman Empire, from Britannia to Syria and from North Africa to the Rhine frontier. Many were small, cave-like underground structures designed to hold only a few dozen worshippers. A notable example is the Mithraeum beneath the Basilica of San Clemente in Rome, where the cult scene is still visible.