This dissertation investigates nineteenth-century narrative representations of the Cossacks—multi-ethnic warrior communities from the historical borderlands of empire, known for military strength, pillage, and revelry—as contested historical figures in modern identity politics. Rather than projecting today’s political borders into the past and proceeding from the claim that the Cossacks are either Russian or Ukrainian, this comparative project analyzes the nineteenth-century narratives that transform pre-national Cossack history into national patrimony. Following the Romantic era debates about national identity in the Russian empire, during which the Cossacks become part of both Ukrainian and Russian national self-definition, this dissertation focuses on the role of historical narrative in these burgeoning political projects. Drawing on Alexander Pushkin’s Poltava (1828), Nikolai Gogol’s Taras Bulba (1835, 1842), and Taras Shevchenko’s Haidamaky (1842), this dissertation traces the relationship between Cossack history, the poet-historian, and possible national futures in Ukrainian and Russian Romantic literature. In the age of empire, these literary representations shaped the emerging Ukrainian and Russian nations, conceptualized national belonging in terms of the domestic family unit, and reimagined the genealogical relationship between Ukrainian and Russian history. Uniting the national “we” in its readership, these Romantic texts prioritize the poet-historian’s creative, generative power and their ability to discover, legitimate, and project the nation into the future. This framework shifts the focus away from the political nation-state to emphasize the unifying power of shared narrative history and the figurative, future-oriented, and narrative genesis of national imaginaries.