The doctrine of purgatory - the state after death in which Christians undergo punishment by God for unforgiven sins - raises many questions. What is purgatory like? Who experiences it? Does purgatory purify souls, or punish them, or both? How painful is it? Heaven's Purge explores the first posing of these questions in Christianity's early history, from the first century to the eighth: an era in which the notion that sinful Christians might improve their lot after death was contentious, or even heretical. Isabel Moreira discusses a wide range of influences at play in purgatory's early formation, including ideas about punishment and correction in the Roman world, slavery, the value of medical purges at the shrines of saints, and the authority of visions of the afterlife for informing Christians of the hereafter. She also challenges the deeply ingrained supposition that belief in purgatory was a symptom of barbarized Christianity, and assesses the extent to which Irish and Germanic views of society, and the sources associated with them - penitentials and legal tariffs - played a role in purgatory's formation. Special attention is given to the writings of the last patristic author of antiquity, the Northumbrian monk Bede. Heaven's Purge is the first study to focus on purgatory's history in late antiquity, challenging the conclusions of recent scholarship through an examination of the texts, communities and cultural ideas that informed purgatory's early history.