The European Union has established itself as a significant international legal actor. Understanding the EU's actions on the international plane requires an understanding of its constantly evolving constitutional and legal framework. This book presents the law of EU external relations in a concise and accessible manner for students, practitioners, and academics in the field. It combines chapters on the general basis of the Union's external action and its relation to international law with chapters which further explore the law and practice of the EU in the specialized fields of external action such as the common commercial policy, development cooperation, cooperation with third countries, humanitarian aid, the enlargement and neighbourhood policies, the external environmental policy, and the common foreign and security policy, as well as a chapter specifically dedicated to EU sanctions and countermeasures. Carefully selected primary documents are accompanied with analytic commentary on the issues they raise and their significance for the overall structure of EU external relations law. The primary materials selected include many important legal documents that are hard to find elsewhere but give a vital insight into the operation of EU external relations law in practice.