Le culte de Mithra a achevé de s’installer dans l’Empire romain au IIIe siècle. Il a prospéré dans une période de mutation des pratiques religieuses. En dispensant par initiation un accès à ses rites, en appliquant des épreuves théâtralisées de progression, en imposant le secret et en provoquant une expérience relationnelle avec son dieu, sa proposition religieuse s’inscrivait dans la phénoménologie des mystères antiques. Mithra a été reçu en territoire romain et dans les provinces occidentales de l’Empire par des hommes d’horizons géographiques et ethniques variés, mais réunis par des caractères communs quant à leur niveau social et culturel. Les mobiles qui les ont attiré ont pu être l’attrait d’un réseau communautaire, la recherche d’une valorisation existentielle dans ce réseau interactif, l’accès à une initiation spirituelle dans un contexte culturel avancé ou peut-être la curiosité. Les expressions initiatiques transcrites par les mithraea symbolisent la libération de l’individu dans le monde, sans prôner de remise en question de la structure sociale. Même s’il est demeuré au rang des cultes privés ou étrangers dans le système impérial, avec un dieu d’origine orientale, mais plutôt mis en scène sous une forme orientalisée, avec une structure mystérique grecque et une éthique stoïcienne, il résulte de cette recherche qu’on doit considérer le culte de Mithra en Occident sous l’angle réceptif d’un culte romain, mais avec déjà, dans cette époque de transformation une forte propension à l’universalité. / The worship of Mithra finished settling down in the Roman Empire in the IIIth century. He prospered for a period of transfer of the religious practices. By dispensing by initiation an access to its rites, by applying theatralized tests of progress, by imposing the secret and by causing a relational experience with his god, his religious proposal joined the phenomenology of the antique mysteries. Mithra was received on Roman territory and in the western provinces of the Empire by men of varied geographical and ethnic horizons, but gathered by common characters as for their social and cultural standing. The motives which attracted them were able to be the attraction of a community network, the search for an existential valuation in this interactive network, the access to a spiritual initiation in an advanced cultural context or maybe the curiosity. The initiatory expressions transcribed by mithraea symbolize the liberation of the individual in the world, without advocating of questioning of the social order. Even if it lived to the rank of private or foreign cults in the imperial system, with a god of oriental origin, but rather staged under an orientalized shape, with a Greek mystical structure and a Stoic ethic, it results from this research that we have to consider the cult of Mithra in the West under the susceptible angle of a Roman cult, but with already, in this period of transformation, a strong propensity in the universality.

The Mysteries of Mithras, dedicated to the eponymous Persian divinity, was one of several mystery cults of the ancient world. It flourished during the second and third centuries CEthroughout the Roman Empire, but with special frequency in Italy and the frontier provinces along the Rhine and Danube. Those initiated into the Mysteries met in special cult rooms or complexes knownto themas "caves", but which in modern research are most commonly referred to as mithraea(s. mithraeum). Their defining features are a central aisle flanked by podiawith a cult niche at the far end, typically displaying the bull-slaying Mithras. Since the late 19thcentury, the research of the cult has traditionally concerned itself with issues regarding the cult'sorigins as well as its doctrines and beliefs. However, it has been noted that this traditional approach includes an undervaluing of both the role of ritual within the Mysteries and the design of the mithraeumwith regards to the enacted rituals.By instead focusing on these shortcomingsthe present study will suggest a practice-oriented way of viewing the role of ritual within the cultand how this might have related to the physical space of the mithraeum.