EMU is at the centre of the stage for the crisis that spreads criticisms on the lack of instruments to correct asymmetric shocks within the Euro-zone. This bears a social dimension for the long-lasting period of negative growth, massive unemployment and social inequality due to the uneven distribution of costs. EMU is now envisaged by many sectors as a rotten piece in the realm of European integration. This turmoil is the context for the book. Some debates on the future of EMU are by large contaminated by emotional analyses that fail to recognise that desirable solutions clash against the political context (absent political willingness both at the domestic and at the EU levels), as well as from rigidities coming from EU treaties. The main purpose of this book is to provide a context for understanding the limits of change to EMU. It is necessary to understand the theoretical underpinnings of EMU, both at the foundational stage and for the Euro-zone governance. The awareness of some of theories that lie at the heart of EMU and explain subsequent changes helps to understand the evolution of the Euro-zone and to capture the obstacles that some ambitious proposals for change face.