There is an immense tax treaty network between European Union Member States and third countries. These tax treaties are bilateral conventions, governed by international law. At the same time, these agreements are part of the internal law of the various Member States. European Community (EC) law has supremacy over domestic law and, therefore, over tax treaties as well. Consequently tax treaties must conform with EC law. This book examines the areas of tension between EC law and tax treaty law. Since most rules of primary and secondary law are directly applicable, they can substantially impact the implementation of tax treaty provisions and consequently result in serious practical ramifications. As part of its analysis this work devotes particular attention to the growing number of decisions of the European Court of Justice concerning fundamental freedoms and direct taxation. Thus, this book provides an up-to-date and comprehensive analysis of the interaction of national tax law, double tax treaties, and the EC Treaty.