Citizenship is an eminent example of the dynamic development of European constitutional concepts. From a status to which the member states wished not to attach any significant directly effective new rights, the Court of Justice has declared European citizenship to be ‘the fundamental status of nationals of the member states’ (Grzelczyck) and has given one of the prime citizenship rights, the freedom to reside in member states, direct effect. This development and in particular the interplay between constitutional developments at European Union and at national level regarding citizenship deserve reflection. We focus on the extent to which citizenship constitutes an exclusive bond with a political community which distinguishes those who are its members from those who are not.