1 Introduction

The first chapter of the book starts with some definitions of important terms used throughout the book such as ‘international law of taxation’, ‘international tax law’, or ‘the international tax regime’. Afterwards, reference is made to the history of the international tax regime. Moreover, the competences and the functioning of some of the most important institutions relevant for the international law of taxation are discussed. This includes the UN, the OECD, the Inclusive Framework, and the Global Forum. A particular chapter is dedicated to the question of sovereignty in tax matters. This is necessary for a comprehensive understanding of the sources of the international law of taxation as outlined in Chapter 2.