To many people, the term "medieval cosmopolitanism" might seem like a contradiction in terms. Even though the European Middle Ages is period that is routinely excluded from debates about transnational cultural phenomena, medieval travel narratives brim with episodes of encounter with people far away from the places where they were born: Parisian jewelers working for the Great Khan at the ends of the known world, translators working for the Sultan of Cairo who speak perfect French, Spaniards who live among the Aztecs long before Mexico is "discovered." These examples of medieval cosmopolitanism serve as a rejoinder to stereotypes that depict the Middle Ages as parochial and insular. My dissertation argues that it is not enough to challenge the myth of medieval provincialism; it demonstrates that we must also understand how that myth has shaped the theories and methodologies that we use to study the Middle Ages. Differently Centered Worlds analyzes written representations of travelers' bodies in order to demonstrate how literary scholars might contribute to the formation of new theories and methodologies that are capable of dealing with a Middle Ages on the move. My study of the traveler's body is engaged in recovering a range of voices and identities that characterize the pre-modern engagement with the global, tracking movements and investments in the foreign by groups traditionally positioned outside histories of travel: slaves, refugees, peasants, sexual minorities, and bored housewives. It aims to contribute to a growing body of knowledge about the inter- and transnational affinities of socially marginal people in a number of historical epochs while also laying the theoretical groundwork for a more representative cultural history of medieval cosmopolitanisms.