This volume celebrates the first fifty years of the International Centre for Settlement of Investment Disputes (ICSID) by presenting the landmark cases that have been decided under its auspices. These cases have addressed every aspect of investment disputes: jurisdictional thresholds; the substantive obligations found in investment treaties, contracts, and legislation; questions of general international law; and a number of novel procedural issues. Each chapter, written by an expert on the chapter’s particular focus, looks at an international investment law topic through the lens of one or more of these leading cases, analyzing what the case held, how it has been applied, and its overall significance to the development of international investment law. These topics include: - applicable law; - res judicata in investor-State arbitration; - notion of investment; - investor nationality; - consent to arbitration; - substantive standards of treatment; - consequences of corruption in investor-State arbitration; - State defenses - counter-claims; - assessment of damages and cost considerations; - ICSID Arbitration Rule 41(5) objections; - mass claims, consolidation and parallel proceedings; - provisional measures; - arbitrator challenges; - transparency and amicus curiae; and - annulment. Because the law of international investment continues to grow in importance in an ever globalizing world, this book is more than a fitting way to mark the past fifty years and to welcome the next fifty years of development. It will prove both educational for practitioners new to the field and informative for seasoned investment lawyers. Moreover, the book itself is a landmark that will be of great value to professionals, scholars and students interested in international investment law.