From the middle of the first millennium CE, South Asia saw the emergence and rise of Tantrism within all of its major religious traditions: Śaivism, the Vaiṣṇava Pāñcarātra, the Buddhist Mantrayāna, and Jainism. Despite the fact that Tantrism grew to become such an integral part of the religious landscape, our understanding of how early Tantric communities were actually organized and how they positioned themselves in society is still limited. This collection of articles by leading scholars offers new insights into the socio-religious history of premodern Tantric traditions.