For most of its history, the public figurehead of what is now the European Union has been the President of the European Commission. Individual Presidents for reasons of personal temperament, the attitude (not always helpful) of the most powerful Member States, or the broader political and economic context - have had varying impact on the development both of the Commission and of the Union as a whole, but most have left a legacy of some kind. In this volume, the editors have for the first time assembled a complete collection of specially written concise political biographies of all eleven of the Presidents from Walter Hallstein (1958-1967) to Jose Manuel Barroso (2004-2014). This portfolio of pen portraits makes fascinating reading in its own right, and to this the editors have added a thematic overview, drawing out the many similarities and contrasts between the Presidents and providing some general conclusions about what one President, Roy Jenkins, termed 'an impossible job'. This is a book of relevance to all who are interested in the history of the EU and its institutions and wish to understand how it got to where it is today. And, as the EU confronts immense challenges under the new Commission presidency of Jean-Claude Juncker, it also provides many signposts and pertinent historical analogies for the future.