The European Union is on the brink of fundamental change. Just as the EU is about to enlarge radically, the Convention on the Future of Europe may transform it into a political entity governed by a constitution. This timely volume brings together a world–class group of scholars and practitioners to examine the fundamentals of integration in an expanding EU. The contributors are a mix of leading theorists and practitioners, spanning the principal disciplines with an interest in European integration. They explore key questions about the nature of the EU, its structure and procedures, but also take a more profound look at the social, political and economic dimensions of integration and their relevance for a revitalised European Union.