In Roman society of the third century CE, marked by deep innovative drives and by the search for new intellectual models and new forms of transcendence, a comparative reading of christianity and mithraism appears indispensable for understanding these religious phenomena. For a cult like mithraism the voice of archaeological sources is particularly significant and almost exclusive. In fact, literary sources are largely deficient especially when compared with those relating to christianity. After more than a century of systematic research, the construction of a proper Mithraic archaeology is the most appropriate and adequate response to the questions posed by advancing research and discoveries. The international value of a topic that directly involves not only archaeologists but also historians, epigraphists and specialists in history of religions was well demonstrated by the major traveling exhibition on “Mithra plongée au coeur d’un culte romain” (2021-2022).