The book analyses the processes of institution and identity building of the European Union Diplomatic Service working on matters of foreign policy and external economic relations, both in Brussels and in the Commission's Delegations across the world. The book examines what images high ranking officials in charge of the EU foreign policy hold of the EU's and of the Commission's role in international politics. The author explains how the EU diplomatic network came into being, how it is currently organised and what changes are likely to take place with the implementation of the Lisbon Treaty. Through an empirically grounded and theoretically informed approach, it analyses how their idea of Europe is enacted through the Commission's diplomatic practices. Carta demonstrates how processes of socialization can bring about different foreign policy priorities, role conceptions and identities. This book makes an important contribution to debates about the idea of Europe, the European Union and European foreign policy, as well as more generally to the analysis of how ideas, identities and self-images shape the daily practice of large institutional bodies in international politics. It will be of interest to students and scholars of European politics, foreign policy, international organizations, international relations and diplomacy.