Imperial frontiers have been a topic of research and a source of fascination for decades. This volume deals with the Carolingian Empire, particularly Italy, collecting fifteen essays on the military, economic and social function of the frontier; how it was ideologically conceived and physically realized from Saxony to Catalonia across the Alps and the Danube. In a rich diversity of perspectives and themes, the concept of frontier is used in its political, ideological, normative, and cultural meanings. Aim of the volume is to offer a comprehensive picture of Carolingian frontiers against the background of the broad debate on empires and frontiers.