Why dedicate a book of over five hundred pages to a religion as stone-dead as that of one of thousands of ancient Mediterranean cities?
For the choice of the city, it is easy to find arguments. Rome was one of the most successful cities ever to build an empire, which comprised millions of square kilometers and lasted close to a millennium. It was and is a cultural and religious center, even if the culture was frequently Greek and the religion is known nowadays as Catholic Christianity. Finally, Rome remains a tourist center, a symbol of a past that has succeeded in keeping its presence in school books and university courses. And yet, what has this all to do with Roman religion?
“Roman religion” as used here is an abbreviation for “religious signs, practices, and traditions in the city of Rome.” This is a local perspective. Stress is not given to internal differences between different groups or traditions. Instead, the accent is placed on their common history (part I) and range of media (part II), shared or transferred practices (part III), and the social and institutional context (part IV).
Many religious signs were exchangeable. The fourth-century author of a series of biographies on earlier emperors (the so-called Historia Augusta) had no difficulties in imagining an emperor from the early third century venerating Christ among the numerous statuettes in his private rooms. Gestures, sacrificial terminology, the structure of hymns were equally shared among widely varying groups. Nevertheless some stable systems, sets of beliefs, and practices existed and were cared for by specialists or transported and replicated by traveling individuals. They were present in Rome, effective and affective, but a set of beliefs, a group, or even an organization had a history of its own beyond Rome, too. Here, the local perspective is taken to ask how they were modified in Rome or the Roman period (part V).
“Rome,” the name of the city, finally, is merely a cipher for the Roman empire. In the long process of its expansion and working, the religious practices of the center were exported, in particular the cult of the living or dead emperors and the cult of the dominating institutions, the “goddess Rome” (dea Roma) or the “Genius of the senate” (Genius senatus). This was part of the representation of Roman power to its subjects (see chapter 22), but at the same time it offered space for the activities of non-Roman local elites to get in touch with the provincial and central authorities and to distinguish themselves from their fellow-citizens (chapter 23). As communication between center and periphery - and other attractive centers in a periphery that was marginal in administrative terms only - these activities touched upon the religious practices in the city of Rome, too. “Roman religion” cannot be isolated from the empire, at least for the imperial period, if we take for granted the character of earlier Rome as a Hellenistic city on the margins of Hellenic culture (Hubert Cancik, p. c.). Again, that perspective holds true in both directions. The history of Mediterranean religions in the epoch of the Roman empire must acknowledge the fact that Persian Mithraism, Hellenistic Judaism, and Palestinian Christianity were Roman religions, too. It is the final section of this book that explicitly takes this wider geographical stance (part VI).