Since 1989 the concept of 'civil war' has taken on new salience in international relations. Significant inquiries into inter-ethnic violence emphasising studies of political community, identity, sovereignty, and political organisation have dominated the study of civil war in the past decade. Processes of social denationalisation of national identity have become more prevalent in everyday politics. In this book leading European scholars analyse the proposition that the world has returned to a system of neo-medievalism over a decade after the end of the Cold War. The chapters explore the idea that a system of overlapping authorities and crisis-crossing loyalties have arguably eliminated the absolute authority claimed and exercised by sovereign states. This book was previously published as a special issue of the journal Civil Wars.