Historians today like to preach the virtues of comparison and cross-national work. In the last decade, cross-national histories have prospered, yielding important work in the subjects as diverse as the transatlantic trade in slaves and the cultures of celebrity. In the meantime, comparative history has also enjoyed a renaissance, but what is largely missing in the rush beyond the nation is any sense of how to tackle this research. This volume brings together scholars who have worked either cross-nationally or comparatively to reflect upon their own research. In essays that engage practical, methodological, and theoretical questions, these contributors assess the gains—but also the obstacles and perils—of research that traverses national boundaries. Drawn from the subject-areas that have attracted the most comparative and cross-national attention: war, welfare, labor, nation, immigration, and gender. Taken together, these essays provide the first critical analysis of the cross-national turn in European history.