In Rome on Christmas Day 800 Charlemagne, the Frankish king, was acclaimed 'most August, crowned by God, great and peacemaking emperor'. This event transformed the nature of his rule, marked the re-emergence of the ideas of empire in the early medieval West, and changed the history of western monarchy. But why was Charlemagne acclaimed as peacemaking emperor? How had peace come to be seen as a central component of western European rulership? Drawing upon a wealth of contemporary sources this study explores the image of peaceful rulership in western Europe from the earliest phase of post-Roman polities - Vandal Africa, Gibichung Burgundy, Ostrogothic Italy - to the Carolingian and Anglo-Saxon worlds. From poems celebrating Vandal baths that evoked stoic concepts of cosmic order to seventh-century Visigothic poetry and early Irish theorising on the ideal ruler, this book offers a comprehensive vision of how the relationship between ideas of kingship and peace was explored through poetry, political thought, ritual and the writing of history across Europe in the early Middle Ages. Peace emerges in these centuries as a concern for kings and emperors, their celebrants, critics, and advisors. It was no less an issue for those whom they ruled. From prayers for safe travel and blessings for new houses through to medieval pilgrim accounts praising the surprising security of ninth-century Egypt's roads, this study asks what peace meant to early medieval people, and how collective expectations and royal intentions met. This is the first full scholarly exploration of the relationship between the idea of peace and rulership through Europe's formative centuries, setting the shifting terms of that relationship in their full historical, political and cultural context. In the process it offers new insights to the reception of late antique thought and imagery in the earlier Middle Ages, the range and distinctiveness of early medieval political thought, and the intellectual vitality of the period AD 500 to 900.