My book analyzes the politics of nation-formation in Bosnia-Herzegovina from 1840 to 1914, a crucial period that witnessed the rise of several competing and converging national movements in the Ottoman and Habsburg Balkan provinces. My project reveals the interconnectedness of national movements across Central Europe, the Balkans, and the Middle East and challenges the periodization breaks and geopolitical divisions that define these fields. By analyzing how Serbian, Croatian, and Muslim activists discovered and fostered identification with their co-nationals in Bosnia, who appeared simultaneously as their “brothers” and their “enemies,” my study outlines new methodological positions from which the complex workings of nationalism can be better understood. Focusing on problems that aspiring patriots faced in three key areas—language, suffering, and political activism—my book argues for closer scrutiny of the problem of national identification, contending that identification can be best explored as a dynamic realm of political imagination capable of ascribing both sameness and radical difference to existing and potential co-nationals. My book thus analyzes the formative engagements with the question of Bosnia’s “proper” national belonging that produced both a lasting sense of Yugoslav unity and troubling division, while also illuminating the competing visions of democracy, modernity, and community that inhere in nation-building projects.