This chapter traces the origins of International Relations (IR) scholarship from the outbreak of the First World War to the making of the peace. It follows a set of pioneering thinkers and pressure groups across Europe and the United States to demonstrate both the intellectual roots and the practical infrastructure of the emerging discipline. The chapter begins by reviewing the state of international affairs on the eve of the war which inspired a set of writings on economic interdependence and world order. The second section shows how the conflict itself prompted authors to reflect on the causes of war and the conditions for peace. The third section examines the intellectual preparation of the post-war order within an emerging community of IR experts. The final section reveals how the founders of IR contributed as government advisors to the Paris Peace Conference and, simultaneously, laid the institutional foundations of the discipline. As a result, this chapter concludes, the origins of IR were deeply intertwined with wartime events and inspired by the making, not just interpreting, of international politics.