This book offers a historically sensitive ethnography of the zār ṭumbura spirit possession cult, associated with descendants of African slaves who live mainly in the area of Greater Khartoum, Sudan. It considers the history and transformations of ṭumbura, from the 19th-century slaving era to the present post-Islamist autocracy. The chapters examine the ṭumbura spiritual universe and ceremonial life, its relation to the more popular female cult of zār borē and to other now extinct forms of celebrating the zār spirit(s), as well as ṭumbura's combination of possession, sorcery, ancestor worship and ṣūfī piety. Based on long-term fieldwork, the study shows how successive generations of subaltern cult devotees construct a positive self-identity based on an alternative reading of Sudanese history. The author explores the edges of Sudanese Islamic religiosity and probes the limits of anthropological classifications concerning religious experience. Situating ṭumbura in its wider context, the book discusses subaltern modes of historicity in their articulation with dominant conceptions of history, traces the legacy of slavery and the role of memory and invites comparisons with Middle Eastern, Sahelian and even New World societies regarding stigmatised identities, slavery, race, memory and history. It will be of interest to scholars of anthropology, history, religious studies, Islamic studies and African studies.