Volume X of The Cambridge History of International Law offers the most 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 cliche 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.