Mithras in Carnuntum – A cult between military and mystery

The cult of Mithras is one of the most fascinating religious phenomena of the Roman Empire. As a mystery religion, it was particularly widespread in military circles and reached even the most remote regions of the empire. Mithras was regarded as a protective god, bringer of light, and cosmic savior—he connected this world and the next, humans and the cosmos, through symbolic imagery and secret rituals. This cult took on particular significance in Carnuntum. Numerous archaeological finds from several places of worship demonstrate how closely it was interwoven with the military and social life of the city.

The Roman Mithras probably originated from a complex synthesis of ancient Iranian, Asia Minor, and Hellenistic-Roman ideas. However, it did not appear in the West as a mere import of a foreign religion, but as a conscious new creation with its own imagery, ritual language, and organizational form—tailored to the needs of Roman male communities. Probably originating in the late 1st century BC or early 1st century AD, the cult spread rapidly throughout the empire – mainly through Roman legionaries who first encountered it in Asia Minor. It found fertile ground along military roads, in forts, camps, and border towns such as Carnuntum.

Tauroctony relief from Carnuntum, 3rd century AD (Inv.-Nr. CAR-S-97) - © Landessammlungen NÖ 

Carnuntum provided an ideal environment for the cult. The legions stationed there—first Legio XV Apollinaris, later Legio XIV Gemina—were not only military forces but also cultural agents. The soldiers, often hailing from different provinces, brought with them a variety of religious traditions that became established in Carnuntum.

The center of the cult of Mithras was the tauroctony – the depiction of the killing of the bull: Mithras, dressed in a cloak and Phrygian cap, kneels on a fallen bull, holds it by the nostrils, and thrusts a sword into its shoulder. He is always surrounded by the same companions – a dog, a snake, a scorpion, a raven – as well as ears of corn sprouting from the animal's tail. What appears to be a sacrificial ritual is in fact a complex system of symbols. As a mystery religion, the cult of Mithras was only accessible to initiates; its contents remained protected by vows of silence. Women were denied access, and many aspects of the cult remain obscure to this day.

Bronze bull from a Mithras group, Carnuntum, 2nd–3rd century - © Landessammlungen NÖ

One of the most convincing interpretations links the imagery of the tauroctony with the astronomical phenomenon of the precession of the equinoxes—that is, the gradual shift of the equinoxes through the constellations. Mithras appears here as the divine ruler of time, who ends the astrological age of Taurus with the death of the bull. He is associated with the constellation Perseus, which appears in the sky above Taurus. The other animals and objects in the tauroctony also correspond to constellations: Scorpio, Dog, Snake (Hydra), Raven, Lion, and Cup once marked positions on the celestial equator.

The cult thus combined astronomical knowledge with a spiritual message. Through seven degrees of initiation—each assigned to a planet—the soul was to ascend through the planetary spheres after death and return to its divine origin. Rituals such as a kind of baptism, mystical wedding, or holy meal served as preparation for this journey.

View of the Mithras grotto in the Carnuntinum Museum - © Römerstadt Carnuntum 

No other place north of the Alps offers such a rich tradition of Mithraic worship as Carnuntum. Five known mithraea—places of worship dedicated to Mithras—have been discovered in the area of the military camp and civilian town. The first sanctuary was found on the Kirchenberg hill in Bad Deutsch-Altenburg as early as 1852: a natural rock cave with cultic furnishings. Although later destroyed by quarrying, important sculptures – including the central bull-slaying image – have been preserved and can now be seen in the Carnuntinum Museum.

In 1894, a spectacular find followed in the Lange Gasse in Petronell: Carnuntum's largest mithraeum was uncovered – a three-nave building with altars, podiums, votive inscriptions, and rich figurative decoration. A reconstructed cult scene from this temple now forms the centerpiece of the Mithras Grotto in the museum. A particularly significant altar from the late 3rd or early 4th century refers to the imperial conference of 308 AD and documents the restoration of the sanctuary – an indication of the continuing importance of the cult in late Roman times:

Other Mithraea—for example, on the Pfaffenbrunnwiese, in the Petronell Castle Park (“Tiergarten”) or on the western edge of Bad Deutsch-Altenburg—attest to the widespread popularity of the cult, even beyond purely military contexts. Finds of snake vessels, altars, and sacrificial remains show that the rituals were performed regularly and intensively.

In late antiquity, the cult of Mithras competed directly with the emerging religion of Christianity. Despite fundamental differences—Christianity was public, communal, and also accessible to women; the cult of Mithras was exclusive, secret, and male-dominated—there were striking parallels: a savior god, a sacred meal, the ascension of the soul, a gradual initiation system, and a ritualized religious life with the promise of salvation. Such similarities led to the question of whether early Christianity had adopted elements of the cult of Mithras or consciously opposed them.

With the religious laws of the Christian emperors, especially under Theodosius I, pagan cults were banned between 391 and 392 AD. Archaeologically, this upheaval is hardly directly apparent in Carnuntum, but by the time the troops withdrew in the early 5th century at the latest, all traces of the cult of Mithras had disappeared.

Lighting of the tauroctony relief with dedicatory inscription from Mithraeum III - © Römerstadt Carnuntum 

The cult of Mithras was an expression of religious practice between heaven and earth, between cosmic order and everyday military life. In Carnuntum, where legionnaires were responsible not only for securing the border but also for cultural impulses, this belief was visibly practiced. The preserved altars, sculptures, and inscriptions, now on display in the Carnuntinum Museum, bear witness to a spiritual system that combined astronomical knowledge, ritual practice, and personal salvation. The presence of Mithras in Carnuntum makes it clear how profoundly and far-reaching religious ideas could develop in the empire.

The museum Carnuntinum - © Römerstadt Carnuntum 

Tip: The topic of religion—including the cult of Mithras—is currently also being impressively covered in the special exhibition 1700 Years of the Council of Nicaea at the Carnuntinum Museum. Those who want to delve deeper into the religious diversity of Roman Carnuntum will also find a wealth of further information, images, and background texts on the city's most important cults, gods, and sanctuaries in the new museum guide to the Carnuntinum Museum. It's well worth a look!