The Roman Mithras is known almost entirely from what his worshippers left in stone rather than in writing, for the cult kept no scripture that survives. At the heart of every sanctuary stood the tauroctony: Mithras, in a Phrygian cap, kneeling on a bull and driving a dagger into its neck while a dog and a serpent leap at the wound, a scorpion grips the bull's genitals, and a raven looks on, flanked by the twin torch-bearers Cautes and Cautopates. The scene is thought to carry an astronomical or cosmological meaning now lost.
Worship took place in small windowless mithraea built to resemble caves, where men, and only men, advanced through seven graded initiations named for the planets, from Raven to Father, and shared a communal meal. The cult spread with the army and the imperial administration from the later first century and was strongest in the second and third. Its name and some motifs descend from the Indo-Iranian god Mithra, but scholars stress that the Roman mysteries were a new creation; the once-popular claim that Christianity simply copied Mithraism rests on parallels that specialists regard as exaggerated or invented.