Archaeological research on Central and South Asia has always engaged with religions, not only because religion is an ubiquitous category in all aspects of the ancient world, but also because religious sites have provided a large quantity of data to further the agendas of diverse academic traditions. Since the early discovery of sites in Bactria and Gandhāra in the nineteenth century, material culture related to religious communities—whether Hellenistic temenoi or Buddhist monasteries—has been approached and interpreted by the lens of Eurocentrism and Colonialism. Depending on the perspective, interactions between religious communities have often been described in vague terms, sometimes omitting local conditions and overemphasising ‘foreign elements’. Today, the potential of interdisciplinary approaches intersecting diverse yet interconnected disciplines such as archaeology, art history, linguistics, and religious studies is well established. Moreover, the contextual analysis of our data by converging diverse sources has also become pervasive. Operating within this context, in this book we defined the concept of ‘religious interactions’ in the broadest sense: either as the meeting of two or more religious communities or as the interaction between different elements of the same religious community.