In recent years, there has been a marked increase in the number of investors seeking compensation from states perceived to have expropriated their projects. Part of the Oxford International Arbitration Series, this book provides a comprehensive guide to expropriation and how it is applied in practice. The book begins by introducing the law of expropriation from a historical standpoint, charting some of the key decisions in the history of expropriation and how it has evolved to become an accepted principle in international law today. It then proceeds to offer a detailed examination of existing case law, from which common substantive principles of the international law on expropriation are drawn out. Relevant international cases from the ICJ, ECHR, Iran–US Tribunal, ICSID, NAFTA, and the ECT are considered to complement the focus on investment treaty arbitration. The book also examines the interplay between expropriation and other standards of treaty protection, namely fair and equitable treatment. The final chapters comment on current trends and assess the relevance of expropriation in the present day.