The study of cultural contact and exchange is intimately connected to the question of agency. Culture, of course, can be transmitted by a number of mechanisms – commodities, ideologies, literary works – as well as people. Material culture, transported as trade, tribute, or booty, can diffuse artistic motifs and technology over great distances. Texts, particularly religious texts, also convey culture over time and space and most particularly between large-scale, urban-based civilizations. The extensive corpus of Chinese translations of the Indian Buddhist canon well illustrates this phenomenon. In the Mongolian era, the fourth mechanism, direct human agency, assumed, as already argued, a very special importance in East–West cultural communication. Given the Mongols' penchant for moving imperial personnel, subject peoples, and specialists from one cultural zone of the empire to another, there were innumerable face-to-face encounters between individuals and communities of the most diverse ethnic, linguistic, and religious backgrounds. In this part of the study, we will investigate the major “brokers” in medieval Eurasian cultural history.

By far the most famous of these intermediaries is Marco Polo. As is well known, from his own day to the present, his travels have been the center of controversy; indeed, many deny that the Venetian ever set foot in China.