This volume sheds light on how lawyers have made sense of, engaged in, and shaped international politics over the past three hundred years. Chapters show how politicians and administrators, diplomats and military men, have considered their tasks in legal terms, and how the field of international relations has been filled with the distinctly legal vocabulary of laws, regulations, treaties, agreements, and conventions. Leading experts in the field provide insights into what it means when concrete decisions are taken, negotiations led, or controversies articulated and resolved by legal professionals. They also inquire into how the often-criticised gaps between juristic standards and everyday realities can be explained by looking at the very medium of law. Rather than sorting people and problems into binary categories such as ‘law’ and ‘politics’ or ‘theory’ and ‘practice’, the case studies in this volume reflect on these dichotomies and dissolve them into the messy realities of conflicts and interactions which take place in historically contingent situations, and in which international lawyers assume varying personas.