This is the first interdisciplinary study of one of the crucial elements of medieval imaginations of the world: blood. It takes a theoretically informed approach to the subject and is thus the first to propose that blood shapes the body as a distinct identity. The author shows that by taking blood and bodies seriously, we gain significant new insights into medieval culture. The author's central thesis is that blood affirms the body as one of the major tenets of medieval thought and identity. 'The body' is not a given, enclosed, unified entity, always already different from the mind and from its surroundings. The concept of such an enclosed body is instead produced by various strategies, of which several use blood. This book will appeal to scholars and students who are interested in the history of the body across a wide range of disciplines: German studies, literature, medieval history, history of religion, history of medicine and gender studies.