This introduces the topic of multilateral drug control, its contemporary relevance and the areas under examination within the book. It highlights the key themes grouped by three overarching focuses: historical, contemporary-legal and international relations theory. It examines the major debates under way in UN drug control and their direct relation to the historical-legal regulatory discussion encapsulated within the book. It outline existing historiography on international drug control and examines more recent developments. It points to continuing gaps in historiography, international relations, legal and policy literature which this book will fill. In particular it highlights the extensive literature on international legal fragmentation and its relevance for drug control debates. It offers an overview of regime theory and international relations approaches, suggesting a new and emerging framework based on evaluating drug control as a ‘regime complex’ in a similar lineage to climate change and intellectual property regimes, which will be covered in a more breadth in the Conclusion.