This book addresses practices of bordering, debordering and rebordering on the territory of the former Austro-Hungarian Monarchy after state borders had been remapped on the negotiation tables of the Paris Peace Treaties following the First World War. As life in borderlands did not correspond to the peaceful Europe articulated in the Paris Treaties, a multitude of (un)foreseen complications followed the drawing of borders and states. The chapters in this book include new case studies on the creation, centralization or peripheralization of border regions, such as Subcarpathian Rus, Vojvodina, Banat and the Carpathian Mountains; on border zones such as the Czechoslovakian harbour in Germany; and on cross-border activities. The book shows how disputes over national identities and ethnic minorities, as well as other factors such as the economic consequences of the new state borders, appeared on the interwar political agenda and coloured the lives of borderland inhabitants. The contributions demonstrate the practices of borderland inhabitants in the establishment, functioning, disorganization or ultimate breakdown of some of the newly created interwar nation-states. The chapters in this book were originally published as a special issue of the journal, European Review of History.