Volume I of The Cambridge History of International Law introduces the historiography of international law as a field of scholarship. After a general introduction to the purposes and design of the series, Part 1 of this volume highlights the diversity of the field in terms of methodologies, disciplinary approaches, and perspectives that have informed both older and newer historiographies in the recent three decades of its rapid expansion. Part 2 surveys the history of international legal history writing from different regions of the world, spanning roughly the past two centuries. The book therefore offers the most complete treatment of the historical development and current state of international law history writing, using both a global and an interdisciplinary perspective.