The legal concept of citizenship of the (European) Union was formally introduced into the EC Treaty in 1993 by the Treaty of Maastricht. EU citizenship comprises a limited bundle of legal rights which citizens can exercise vis-à-vis other Member States and the institutions of the EU and, less often, vis-à-vis their own Member State. Many EU citizenship rights are focused on mobile EU citizens, who have exercised rights of free movement and reside in a Member State other than the one of which they are nationals, e.g. as workers, students or retired persons. The legal status of EU citizenship is derived from Member State citizenship. Only the nationals of the Member States are EU citizens. The Member States have largely unfettered power to determine the scope of their own nationality law, and therefore also who are the citizens of the European Union. However, through the common citizenship of the Union and its core right of free movement, each Member State’s citizenship policies impact on the other Member States.

In this section, we provide information on legal norms, court decisions and policy documents concerning EU citizenship and, in particular, its relationship to national citizenship.