Мithra is a deity of Iranian origin, who was associated with sunlight, luck in military and political affairs, and was also perceived as an impartial arbiter in disputes, conclusion of agreements and even battles. The article is devoted to the origin and formation of the Mithraic cult, as well as its subsequent dissemination and development in Roman Britain. The Mysteries of Mithras is a mystical religious cult, which was known for its specific rites of initiation and was popular among the Roman legions standing on the outskirts of the Roman Empire.