This volume deals with current secessionist movements in states that are or were members of the European Union (EU). It compares the cases of Scotland, Catalonia, and Flanders, which are anchored in three different political systems. However, all three sub-state regions analysed are or were part of the EU multi-level system, and as such, they are subject to the influence of Europeanization. Their secession efforts are influenced by the European framework – including their own EU membership after a possible secession. The three regions, therefore, have different motivations and probabilities for actual secessions. All case studies in this volume are introduced and outlined with theoretical chapters and examined using consistent guiding questions to ensure comparability between the three cases. The analyses are framed by chapters describing other examples of secession processes past and present, and by texts that ask whether federalism or other solutions (so-called ‘third ways’) could offer a path beyond secession.