Sovereignty in Transition brings together a group of leading scholars from law and cognate disciplines to assess contemporary developments in the framework of ideas and the variety of institutional forms associated with the concept of sovereignty. Sovereignty has been described as the main organising concept of the international society of states – one which is traditionally central to the discipline and practice of both constitutional law and of international law. The volume asks to what extent, and with what implications, this centrality is challenged by contemporary developments that shift authority away from the state to new sub-state, supra-state and non-state forms. A particular focus of attention is the European Union, and the relationship between the sovereignty traditions of various member states on the one hand and the new claims to authority made on behalf of the European Union itself on the other are examined. The collection also includes contributions from international law, legal philosophy, legal history, political theory, political science, international relations and theology that seek to examine the state of the sovereignty debate in these disciplines in ways that throw light on the focal constitutional debate in the European Union.