Mithraism

What is attested

The Roman cult of Mithras is known from a large corpus of monuments and inscriptions. M. J. Vermaseren's mid-twentieth-century Corpus Inscriptionum et Monumentorum Religionis Mithriacae runs to some 2,400 entries and has been substantially added to since; published counts of 'Mithraic monuments' vary widely with what is being counted. What the corpus does not contain is a single sentence of Mithraic scripture, a single myth told by an initiate, or a single explanation of the cult's central image by anyone who belonged to it. This is not a gap that further excavation is likely to close in kind: the cult appears never to have produced, or at least never to have circulated, a written theology. Everything said about Mithraic belief is inference from buildings, images and dedications, supplemented by a handful of hostile or philosophically motivated outsiders.

The buildings are the most eloquent evidence. A mithraeum is a small rectangular hall, typically sunk below ground level or built to feel as though it were, with continuous masonry benches running along both long sides and a niche at the far end holding the cult relief. Capacity is characteristically a few dozen at most. Mithraea are consistently small and consistently numerous where the cult was strong — Ostia alone has produced well over a dozen. Whether that reflects deliberate subdivision, independent foundations by separate patrons, or successive periods of use is not recoverable from the buildings. Distribution correlates strongly with the Roman army and the machinery of imperial administration: the Rhine and Danube frontiers, Rome and its port, Britain, the eastern garrisons. The military weighting varies by region, and work on the dedicators has shown the civilian component at Rome and Ostia to be large. The chronology runs from the late first century CE to the late fourth. The mithraeum at Dura-Europos on the Euphrates, built by Palmyrene archers in Roman service, carries dedicatory inscriptions dated to 168 and 171 CE and is among the most securely dated examples.

The cult image is astonishingly stable across that whole range. It shows a young man in eastern dress and a Phrygian cap kneeling on the back of a bull and driving a dagger into its shoulder, his head characteristically turned away from the act. Around him recur a dog and a snake reaching toward the wound, a scorpion at the bull's genitals, a raven, and two torchbearers dressed like the central figure, one holding his torch up and one down; busts of the Sun and Moon occupy the upper corners, and the whole is often set within a cave-like frame or an arch of zodiacal signs. Variants add episodes: a figure emerging from rock, a banquet shared with the Sun, a bow drawn at a rock face. That this repertoire recurs from the Euphrates to the Tyne with such consistency implies transmitted content of some kind. What that content was, no ancient source states.

The internal organisation is better documented than the doctrine. The full seven-grade list survives in one ancient text, a letter of Jerome written in 403 CE: raven, then a second grade whose name is disputed — the manuscripts have been read both as nymphus (bridegroom) and as cryphius (the hidden one), and the painted inscriptions at Santa Prisca support nymphus — then soldier, lion, Persian, sun-runner, father. Archaeology corroborates the seven-fold structure but not the list exactly — the second grade appears at Santa Prisca as nymphus, bridegroom, and the divergence from Jerome is itself a standing problem. Porphyry names individual grades, lions and ravens, in a separate passage. The floor mosaic of the Mithraeum of Felicissimus at Ostia lays out seven panels of symbols along the central aisle between the benches, and painted figures and inscriptions from the mithraeum beneath the church of Santa Prisca in Rome, excavated from the 1950s, show ranked members in procession. Dedications regularly record a man's grade and his relation to a pater, the senior figure of a given community. The named dedicators are soldiers, veterans, imperial slaves and freedmen, customs officials and traders — a distinctly male, mobile, service-oriented cross-section. No securely attested female initiate is known; the one literary text that complicates this, Porphyry's reference to women connected with the rites, is of disputed bearing.

Practice, as opposed to belief, leaves recoverable traces. The benches are dining benches: excavated mithraea yield animal bone, cooking and serving vessels, hearths and lamps in quantities consistent with regular communal meals. Water sources, wells and basins appear frequently enough to suggest ritual use. The Mainz mithraeum produced a large ceramic vessel, published in the 1990s, whose applied relief figures appear to show ritual action involving a seated figure, an archer and initiates in postures of submission — one of the very few objects that seems to depict what actually happened in the room rather than what was depicted on the wall. It remains an object requiring interpretation, and the interpretations differ.

How the rite worked

A mithraeum was a private construction, paid for by individuals whose names are recorded on the dedications: a pater, a patron, occasionally a group of soldiers acting collectively. The Walbrook mithraeum in London produced a marble relief of the bull-slaying dedicated by Ulpius Silvanus, described as a veteran of the Second Augustan legion, who records having been made — either discharged as a veteran or, on the reading many prefer, initiated — at Arausio in southern Gaul. That single stone shows the mechanism of the cult's spread: a man moves with the army, is enrolled somewhere along the way, and pays for the furnishing of a room at the far end of his career. Fittings were bought, altars dedicated, reliefs commissioned locally or imported, and worn-out mithraea were repaired and re-dedicated with inscriptions recording the fact.

Members advanced through grades, but how the grades functioned is disputed. The Ostia mosaic and the Santa Prisca paintings show the seven-fold scheme as an ordered sequence with distinct symbols, and several sources associate the grades with the planets. Whether every member was expected to climb the whole ladder, or whether the higher grades constituted a functional priesthood within a congregation whose ordinary members remained at a lower level, is argued from the relative frequency of grade titles in inscriptions and is not settled. What is clear is that the pater was the ranking figure of a given community and that grade was worth recording publicly on stone.

Initiation involved ordeal and role-play of some kind. Tertullian, writing around 200 CE as a hostile Christian, describes a Mithraic soldier being offered a crown at sword-point in a dark cave and required to refuse it, declaring Mithras his crown. Painted lines beside the ranked figures at Santa Prisca appear to be ritual acclamations, and the Mainz vessel seems to show a kneeling, blindfolded or bound figure confronted by an archer. Several mithraea contain pits, niches and installations that excavators have interpreted as ordeal or concealment features. These are consistent with an initiation involving darkness, physical trial and a scripted refusal, but they do not amount to a reconstructed rite, and the sequence, the words spoken and the meaning attached are unrecovered.

The core regular activity was a meal taken reclining on the two benches, facing the cult relief and each other. The meal is visible in the debris — bone, cooking and serving vessels, hearths — but its scale and cost are not recoverable, and the assemblages vary by site. Some mithraea show deliberate decommissioning in the fourth century — images defaced, altars overturned, deposits sealed — but whether a given case reflects Christian violence, official closure, or an act by the members themselves has to be argued site by site and often cannot be decided.