While the internal energy market is approaching completion, the EU still struggles to put together a coherent design for its external energy relations. This year's events in Ukraine dramatically highlighted Europe's vulnerability, in particular in relation to hydrocarbons. Security of supply has been high on the agenda of European policy-makers for several years, especially in the wake of the last supply crises in 2006 and 2009. Security of supply and the emerging external energy policy are closely interrelated. Evidently, both concepts are of high relevance for EU law. Security of energy supply used to be invoked by Member States against the enforcement of the fundamental freedoms in the internal market before it became one of the objectives of energy policy and triggered a string of legislative and regulatory measures on European level, including the creation of new bodies and the more vigorous promotion of infrastructure. External energy policy is, in many respects, the strategic counterpart to the strife over security of supply and, until recently, was a conglomeration of different measures. This book will follow the manifold ramications of European external energy law and policy, including; the case law, and acquis related to security of supply; project-related interventions, through so-called `pipeline diplomacy'; the relevance of competition law, and international climate change law, for external action; and natural resources law, including shale gas, etc. It will also analyze the EU's bilateral international relations with countries as diverse as Russia, Ukraine, and Switzerland. A particular focus will be the law of multilateral organizations of relevance for European energy policy, such as the WTO, the Energy Charter, the European Economic Area, and the Energy Community. The author is Deputy Director and Head of Legal at the Secretariat of the Energy Community. Given the ever-closer amalgamation of European internal and external market law-and its practical consequences for policy-design, transactions and projects alike-his book will be an indispensable asset for policy-makers, academics, and practitioners.