Historians have long asserted the close connection between ethnology—the practice of systematically describing cultural differences—and the politics of imperial domination. But in this respect, the Ottoman Empire presents an apparent paradox. Despite expanding across a territory that encompassed all or part of over 30 modern nation-states, early Ottoman authors almost avoided describing the cultural diversity of the empire’s subject peoples. Instead, they began to do so at the end of the seventeenth century—long before the onset of Western modernity, but long after the end of Ottoman imperial expansion. How can this apparent paradox be explained? And what lessons might it hold not only for Ottoman history but for a more general understanding of the relationship between knowledge and empire in the early modern world?