The Mongol empire (1206–1368) caused massive transformations in the composition and functioning of elites across Eurasia. While the Mongols themselves obviously became the new Eurasian elite, their small number as compared to the huge territory over which they ruled and their initial inexperience in administrating sedentary realms meant that many of their subjects also became part of the new multi-ethnic imperial elite. Mongol preferences, and the high level of mobility—both spatial and social—that accompanied Mongol conquests and rule, dramatically changed the characteristics of elites in both China and the Muslim world: While noble birth could be instrumental in improving one’s status, early surrender to Chinggis Khan; membership in the Mongol imperial guards (keshig); and especially, qualifications—such as excellence in warfare, administration, writing in Mongolian script or astronomy to name but a few—became the main ways to enter elite circles. The present volume translates and analyzes biographies of ten members of this new elite—from princes through generals, administrators, and vassal kings, to scientists and artists; including Mongols, Koreans, Chinese and Muslims—studied by researchers working at the project “Mobility, Empire and Cross Cultural Contacts in Mongol Eurasia” at the Hebrew University of Jerusalem. The annotated biographies assembled here not only add new primary sources—translated from Chinese, Persian and Arabic—to the study of the Mongol Empire. They also provide important insights into the social history of the period, illuminating issues such as acculturation (of both the Mongols and their subjects), Islamization, family relations, ethnicity, imperial administration, and scientific exchange.