Religion is one of the many potential mediums for emphasizing ethnic difference and highlighting group membership. Particularly in mountainous landscapes, which are difficult for imperial or state powers to control, religion may be a key means of asserting peripherality. The residents of the Mani Peninsula, Greece, converted to Orthodox Christianity during the reign of the Byzantine Empire and maintained this religious affiliation even after Byzantine collapse in 1463 CE, when the region came under Ottoman and, later, Venetian rule. This study reviews the research on Mani’s Byzantine churches to date – much of which is published in Greek – and presents new interpretations of the religious practices of the Byzantine and post-Byzantine communities of Mani. This case study sheds light on the role of religion in rural communities and the potential reasons for religious continuity in peripheral landscapes during periods of social transformation. In particular, the firm adherence of Mani’s residents to Orthodox Christianity emphasized their ethnic difference from the ruling authorities and simultaneously undermined these authorities’ ability to assert hegemonic power in the region.