A new insight into the transnational links non-governmental organizations are developing, which are often more intensive within the EU, even if they extend beyond its borders to the wider world. This multi-disciplinary volume explores the importance of these structures, actors and relations for EU and European governance in the context of the theoretical debate about European integration in the social sciences. This book delivers: - Theoretical chapters examining and discussing the main conceptual perspectives to studying the transnational EU to provide a current overview. - Empirical case studies of transnationalism in practice on transnational party, trade union and police cooperation to transnational education policy-making and transnational consensus-building in EMU governance. This volume will be of great interest to students and researchers of transnationalism and European Union studies within the social sciences.