This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book compares the ways in which the normative idea of citizenship in its national understanding is translated into practice in regard to immigration policies in the UK and Italy. It has been shown that free movement rights at the same time facilitate the firmer control of external frontiers in the context of the expansion of the inner circle of citizenship rights. The book demonstrates that nationality is not functional to a process of 'affective' orientation towards Europe. The ongoing development of the EU has no doubt led to the creation of additional citizenship rights and to a reformulation of immigration policies at the national level. Nationality is the primary criterion to determine eligibility for European citizenship, and citizenship practices at the national level are therefore central in the formulation of immigration policies throughout the EU.