Historical approaches to the study of world politics have always been a major part of the academic discipline of International Relations (IR), and there has recently been a resurgence of scholarly interest in this area. This Oxford Handbook examines the past and present of the intersection between History and IR, and looks to the future by laying out new questions and directions for research. Seeking to transcend well-worn disciplinary debates between Historians and IR scholars, the Handbook asks authors from both fields to engage the central themes of 'modernity' and 'granularity'. Modernity is one of the basic organising categories of speculation about continuity and discontinuity in the history of world politics, but one that is increasingly questioned for privileging one kind of experience and marginalising others. The theme of granularity highlights the importance of how decisions about the scale and scope of historical research in IR shape what can be seen, and how one sees it. Together, these themes provide points of affinity across the wide range of topics and approaches presented here. The Handbook is organized into four parts. The first, 'Readings', gives a state of the art analysis of numerous aspects of the disciplinary encounter between Historians and IR theorists. Thereafter, sections on 'Practices', 'Locales' and 'Moments' offer a wide variety of perspectives, from the longue dur'e to the ephemeral individual moment, and challenge many conventional ways of defining the contexts of historical enquiry about international relations. Contributors come from a range of academic backgrounds, and present a diverse array of methodological and philosophical ideas, as well as their various historical interests.