The book explores how the European Union and its members have been renegotiating Europeanisation and renationalization in response to the multiple crises they faced over recent years. The authors highlight varying understandings of 'crises' in different national and supranational policy and institutional contexts. They show how in some cases these have challenged the legitimacy of European Union norms and institutions and even triggered disintegration, while in others these crises have served as sources of inspiration for European social innovation and political development.