This installment of the Cambridge Histories series is mostly limited to the formative pre-Constantinian period of Christianity, understood not as a monolithic entity but as a hodgepodge of multiple forms of the religion in competition with each other. The volume aims to discuss select issues in ancient Christianity that have received particular attention and generated new perspectives over the last two decades or so, showing the variety and contested nature of almost every aspect of ancient Christianity. The contested nature of ancient Christianity in this volume is twofold: it includes not only how ancient Christians themselves differed over the key issues but also how modern scholars debate the interpretation of the same. The collection of essays is divided into six parts, each exploring this twofold contest over some central issue: (1) history and historiography; (2) the reception history of three key figures in ancient Christianity, Jesus, Peter, and Paul; (3) the articulation of Christian identity in relation to Judaism, Marcionites, Gnostics, Greco-Roman education and philosophy, and the Christian scriptures; (4) the configuration of Christian identity in relation to socioeconomic contexts, imperial ideology, persecution, material culture, and book culture; (5) the disputes over matters of belief, such as creation, God, resurrection, Eucharist, and church offices; and (6) Christian perspectives on aspects of embodiment, including gender, sexuality, slavery, wealth and poverty, and connections with the dead. Each of the 27 chapters is both retrospective and prospective, discussing key trends in the approach to the subject over the last few decades, and setting out questions for future research. No essay claims to be exhaustive, but each is highly informative and provides a solid orientation to the topic. One could also imagine these essays being used by scholars and students alike to grasp the status quaestionis of their subjects.