With the coming into force of the Treaty of Lisbon, the European construction is experiencing dramatic changes. A collection of essays just published by CEPS and edited by Stefano Micossi and Gian Luigi Tosato, analyse the changing equilibria in common policies, institutional settings and mechanisms of legitimisation of the European Union in the 21st century. Even in the wake of the new Treaty, however, the contributors find that the Union remains an entity in flux, in search of its destiny.