This volume offers a new history of Europe's mid-20th century as seen through the lens of its recurrent refugee crises. Borrowing from and adapting E. H. Carr's "The Twenty Years' Crisis," the editors of this volume conceive of the two post-war eras as a single 'forty years' crisis', which enables them not only to explore the continuities and disjunctures across the period but also to challenge established historiographical certainties and master narratives. As the essays in this volume show, the story of the 'forty years' crisis' can be told in very different ways: as one of upheaval, disintegration and suffering, or as one of newly emerging national and international solutions and possibilities; as a 'top-down' history of nations, institutions and policies, or as a 'bottom-up' history of refugees, relief workers and refugee advocates; by assessing the historical developments themselves or their historiographical afterlives. This volume is unique in that it brings these different perspectives together and provides a coherent intellectual framework within which they can be made sense of. "Refugees in Twentieth-Century Europe" represents the first comprehensive treatment of refugees in Europe of this breadth and depth for over a generation.