Carlos Closa is Profesor of Political Science at the University of Zaragoza (Spain). He has been formerly lecturer at the Universidad Complutense de Madrid. He holds a Ph.D. and a M.A. in European integration and cooperation by the University of Hull (UK). He has been Jean Monnet Fellow at the European University Institute (EUI), Florence and, currently, he is Visiting Fellow at the Centre for European Studies (University of Harvard). He is author of Político de la Unión Europea (Madrid: Ed. Complutense; 1997); Spain and the EU (London: Palgrave, 2002), with Paul Heywood (Univ. of Nottingham), and editor of La europeización del sistema político español (Madrid: Istmo, 2001). He has published a large number of articles (in Spanish, English and Italian) on EU citizenship, the EU Constitutional structure and the relationship with the Member States in journals such as Common Market Law Review, Journal of European Integration, Law and Philosophy or the Revista de Estudios Políticos (in Spanish).