Volume X of The Cambridge History of International Law offers a comprehensive and critical discussion of the history of international law in the interwar period to date. Bringing together scholars across various disciplines, the volume aims to go beyond the well-established cliché of the failure of the League of Nations and discusses the huge impact this period had on the post-WWII international legal order. It focuses on the League of Nations as an important milestone to be studied, analysed, and understood in its own right. Using a global perspective, the volume sheds light on the different branches of international law in this dynamic period, during which the discipline underwent a qualitative leap.