Castra Tenebrarum: An examination of the reuse of religious space in the Mithraic and Christian ruins under the Basilica di San Clemente, Rome
Rene Russell (2019) has just completed her MPhil in Classics, focusing on the art and archaeology of early Christianity. She previously studied for a BA in Modern and Medieval Languages at St John’s. In this article for The Eagle, Rene discusses her research into the reuse of religious space in Mithraic and Christian ruins in Rome.
My route into Classics has not been the most conventional; I started out at St John’s in 2019 reading Modern and Medieval Languages with a focus on Spanish and Latin. One thing led to another, and my interest in Latin language and literature spiralled into a fascination with the art and archaeology of the Roman world. Having focused heavily on literature until that point, art and archaeology was something that I had not previously considered as a lens through which to examine the past. However, I have since learnt that taking a multi-lens approach to the ancient world is key. While literature is immensely valuable and can teach us a great amount, combining it with an artistic or archaeological approach can enable a deeper examination of a topic, privileging the voices of those who have left nothing in the literary record.
This joint literary and archaeological approach is one that I have taken in my research this year as part of an MPhil in Classics, which has focused on the art and archaeology of early Christianity. This has included a project on which I recently presented entitled ‘Castra Tenebrarum: An examination of the reuse of religious space in the Mithraic and Christian ruins under the Basilica di San Clemente, Rome’. Castra tenebrarum is Latin for ‘a camp of darkness’, a description used by the fourth-century CE Christian writer Tertullian to refer to Mithraea, the temples in which members of the Cult of Mithras worshipped. While there is a wealth of information available to us about early Christianity, from the letters of Pliny the Younger to martyr texts produced by Christian authors and communities themselves, mystery cults like the Cult of Mithras lack such a literary record owing to initiates being sworn to secrecy.
However, Mithraism has left its archaeological footprint all over the Roman Empire, with Mithraic temples surviving from Rome itself to the fringes of the Empire (e.g. Carrawburgh Roman Fort on Hadrian’s Wall or Dura Europos in Syria). When dealing with mystery cults like Mithraism, an archaeological approach can be extremely useful for revealing information that would otherwise remain hidden.
However, the archaeological record can also be fragmentary, especially in the case of Mithraism, a religion that Christianity considered to be a rival. This rivalry led to the defacement of some Mithraic sites, such as the Strasbourg Mithraeum, whose central cult image was systematically smashed into
more than 360 fragments and scattered throughout the temple. Some Mithraea also had Christian churches built over them; in Rome alone, at least five Mithraea have been discovered beneath or in the immediate vicinity of Christian churches. Other Mithraea suffered both defacement and being built over. Such drastic and violent religious action can be attributed to the fact that early Christians did not deny the existence of pagan gods but believed that they were dangerous spirits who had to be defeated. Despite this religious violence destroying some of the little evidence that could further inform us about Mithraism, this has also led to the preservation of many Mithraic temples.
My project examined one such case of destruction, namely the Basilica di San Clemente in Rome, which was constructed over a Mithraeum. I had the chance to visit the Basilica in 2022 as the recipient of a College travel grant; this opportunity to explore Rome and visit its ancient churches inspired me to take the art and archaeology of early Christianity as the primary focus of my MPhil in Classics.
The site of San Clemente is a complicated one with multiple levels of occupation by different groups, which inspires the question of how much the Christians and Mithraists using the site would have interacted with each other. The two groups were operating in adjacent buildings until the Christians expanded the Basilica, filling in the Mithraeum to provide the foundations for a new apse. The degree of interaction between the two religious groups would have depended on a range of factors, including when Christian worship began at the site, and when the Mithraeum stopped being used. Both dates are impossible to establish for certain: Christian worship at the site may have predated the construction of the Basilica, and the Mithraeum may have fallen out of use earlier than it was filled in. However, there are several indications that worship may have ceased at the Mithraeum as the result of religious violence. This is suggested by the fact that the Mithraic altar was broken or destroyed, and subsequently integrated into Christian-era flooring, while the Mithraeum itself was filled in not long afterwards to provide the foundations for the Basilica’s apse. Literary evidence for Christian antagonism towards Mithraism, as well as archaeological evidence from San Clemente, suggest that the Christians of the Basilica may have capitalised on wider socio-political changes against paganism in order to appropriate Mithraic space for their church.
‘While literature is immensely valuable and can teach us a great amount, combining it with an artistic or archaeological approach can enable a deeper examination of a topic, privileging the voices of those who have left nothing in the literary record.’
I have continued to focus on Christianity this year; as well as learning Ancient Greek (the New Testament was first written in Koine Greek), I am currently working on a thesis examining early Christianity from an
artistic viewpoint. This thesis focuses specifically on depictions of Christ, and how early Christian artists pictured the divine using pre-existing models from pagan tradition. So far this has included figures such as the legendary musician Orpheus, who was used allegorically to represent both David and Christ, and Christ as the Good Shepherd depicted very similarly to depictions of Hermes Kriophoros (Hermes
holding a ram). I find these examples of early Christian art especially interesting and relevant because they were produced at a time when Christian doctrine was still being established and theological debates about Christ were causing immense conflict within the Church. It has been fascinating to research depictions of Christ from this period to see how these debates played out in artists’ attempts to depict such a complicated figure as Christ. Unlike the immortal gods of the Greco-Roman pantheon, Christ was both entirely divine and entirely mortal at the same time, at least according to Nicene Christianity.
I hope to use what I have learnt this year to continue my research with a PhD comparing Christianity with other religions that were becoming popular in the Roman Empire at the same time, namely ‘eastern mystery cults’. My plan is to compare these from an artistic point of view, examining how their focus on ‘foreign’ imagery such as Egyptian animalheaded gods in the Cult of Isis, or Phrygian caps in the Cult of Mithras, might have aided the propagation and popularity of each cult. I aim to shed light on this topic by examining how early Christianity’s iconography compared to that of other religions and cultic groups, especially relating to the degree of assimilation with the visual language of pre-existing Greco-Roman artistic tradition.