2 J. Shaw impact upon the future of EU citizenship. This discussion is prefaced by an initial exploration of the challenges and complexities of EU citizenship and of the relationship between citizenship and concepts of integration and Europeanisation. Challenges and complexities of EU citizenship The current difficulties faced by the European Union are many and varied. They include the pressures caused by the UK’s Brexit vote, the effects of increasingly illiberal, populist and anti-constitutionalist regimes in Hungary and Poland, the lingering impacts of the financial crisis, among them austerity and challenges to the health of the Eurozone, and the continued aftermath of the migration/refugee crisis. These all raise questions about the vitality of citizenship of the European Union as a political, socio-economic and constitutional construct of a supranational kind, and many of them are debated in different ways by the various multi-author ‘forums’ presented in this book. Whether these difficulties do or do not pose an existential threat to the EU and thus to EU citizenship lies beyond the scope of this essay. Even so, contemplating the possibility of disintegration and/or de-Europeanisation is central to the task of reinterpreting EU citizenship, 25 years after it formally entered into force through the Treaty of Maastricht in 1993. This is because of the centrality and overwhelming importance of the Brexit challenge (both for the individuals directly affected and also for the historical trajectory of the European Union), to which we will return later in this short reflection on some of the ‘constitutional’ characteristics of EU citizenship. It is important to remark, however, that at the current stage of the European integration, no person deprived of their EU citizenship through dissolution of the Union or departure of a member state would normally be at risk of losing their national citizenship and their anchor within the system of states, their ‘right to have rights’.2 Although the functions and forms of citizenship are dispersed across the multi-level structure of the EU polity and EU citizenship is established constitutionally in Article 9 TEU and Articles 20 and 21 TFEU, at the present time states retain a monopoly over determining who their citizens are, and would continue to do so were the EU to dissolve in the future. At whatever point we choose to ‘stop time’ and write a historical reinterpretation of the EU’s experiment with a form of supranational citizenship, it will always be a complex and contested story. It is important to resist the 2 Arendt, H. (1967), The Origins of Totalitarianism. London: George Allen & Unwin, 296.