This module acts as an entry point into debates about the role of international law in world politics. It is intended for students who have had no previous background in international law. The aim is to introduce students to the controversies surrounding the use of the word ‘law’ in international relations and the key theoretical and applied issues. By the end of the module students should have a good grasp of central concepts, such as ‘custom’ and ‘treaties,’ of theoretical perspectives such as legal positivism and the legal process school and of the content and significance of international law in certain key areas. The module is divided into three sections. The first examines the nature of law in the ‘anarchical’ context of international society and various conceptual and theoretical issues associated with that debate. The second considers the evolution of international law from the earliest examples of legal norms in international relations, through the emphasis on natural law, to the modern era. The third discusses the sources and content of legal norms in four key areas: the use of force, human rights, war crimes and the environment, concluding with a discussion of the future of international law in the light of arguments that contemporary international law is moving from a primary concern with order in international relations to a concern for international justice.