The ongoing European crisis brings to the forefront questions about the future of the social aspect of European integration. Socializing Europe - Solidifying EU Citizenship addresses these questions by focusing on the evolution of social rights of EU citizens. It presents a detailed analysis of current trends in approaching the development of the social dimension of EU citizenship at both the European and national level. Following a sharp critique of the existing approaches and their consequences in this field of European integration, the book proposes a novel way of addressing its future development. The principle of subsidiarity - comprising both its positive and negative side - is advanced as an appropriate alternative and useful tool for coherent, transparent and legitimate construction of social rights of EU citizens.