Roman temples and mithraea

Most of the temples in this atlas are mithraea, the small sanctuaries of the cult of Mithras. A mithraeum was either an adapted natural cave or a building imitating one: a single entrance or vestibule facing an apse with an altar, and between them the “cave” with raised benches along the side walls, where the initiates reclined for a common meal. There was typically room for 15 to 30 diners and very rarely for more than 40. The centrepiece of every mithraeum was a representation of Mithras killing the bull, the tauroctony. The buildings were sunk below ground, windowless, small, externally undistinguished and cheaply built, which is why they survive as low foundations under a roof rather than as standing architecture.

The cult appears suddenly in the archaeological record in the last quarter of the 1st century AD and was popular in the Roman army from the 1st to the 4th century; it was suppressed by the end of the 4th century. Its members were men only: soldiers above all, but also merchants, customs officials and minor bureaucrats, with considerable numbers of freedmen and slaves. Mithraea are found in considerable numbers along the Rhine and Danube frontier.

In Slovenia the place to see them is Poetovio, today’s Ptuj, which had been the base camp of Legio XIII Gemina and was granted city status by Trajan in 103 as Colonia Ulpia Traiana Poetovio, in the province of Pannonia. The first mithraeum, in Hajdina west of the town, and the third, on Zgornji Breg, are each presented in situ under a protective building together with their altars and reliefs; both are monuments of national importance. Elsewhere the “temple” label covers whatever the Slovenian heritage register records as a sanctuary, such as the early Roman temple at the foot of Rifnik hill. Each entry says what is actually visible and whether the building is open to visitors.