This groundbreaking book examines the role of rulers with nomadic roots in transforming the great societies of Eurasia, especially from the thirteenth to sixteenth centuries. Distinguished historian Pamela Kyle Crossley, drawing on the long history of nomadic confrontation with Eurasia’s densely populated civilizations, argues that the distinctive changes we associate with modernity were founded on vernacular literature and arts, rising literacy, mercantile and financial economies, religious dissidence, independent learning, and self-legitimating rulership. Crossley finds that political traditions of Central Asia insulated rulers from established religious authority and promoted the objectification of cultural identities marked by language and faith, which created a mutual encouragement of cultural and political change. As religious and social hierarchies weakened, political centralization and militarization advanced. But in the spheres of religion and philosophy, iconoclasm enjoyed a new life. The changes cumulatively defined a threshold of the modern world, beyond which lay early nationalism, imperialism, and the novel divisions of Eurasia into “East” and “West.” Synthesizing new interpretive approaches and grand themes of world history from 1000 to 1500, Crossley reveals the unique importance of Turkic and Mongol regimes in shaping Eurasia’s economic, technological, and political evolution toward our modern world.