Peacemaking in the Middle Ages explores the making of peace in the late-twelfth and early thirteenth centuries based on the experiences of the kings of England and the kings of Denmark. From dealing with owing allegiance to powerful neighbours to conquering the ‘barbarians’, this book offers a vision of how relationships between rulers were regulated and maintained, and how rulers negotiated, resolved, avoided and enforced matters in dispute in a period before nation states and international law. This is the first full-length study in English of the principles and practice of peacemaking in the medieval period. Its findings have wider significance and applications, and numerous comparisons are drawn with the peacemaking activities of other western European rulers, in the medieval period and beyond. This book will appeal to scholars and students of medieval Europe, but also those with a more general interest in kingship, warfare, diplomacy and international relations.