During the thirteenth and fourteenth centuries religious zeal nourished by the mendicants’ sense of purpose motivated Dominican and Franciscan friars to venture far beyond Europe’s cultural frontiers to spread their Christian faith into the farthest reaches of Asia. Their incredible journeys were reminiscent of heroic missionary ventures in earlier eras and far more exotic than evangelization during the tenth through twelfth centuries, when the western church Christianized Eastern Europe and Scandinavia. This new mission effort was stimulated by a variety of factors and facilitated by the establishment of the Mongol Empire, and, as the fourteenth century dawned, missionaries entertained fervent but vain hopes of success within khanates in China, Central Asia, Persia and Kipchak. The reports these missionaries sent back to Europe have fascinated successive generations of historians who analyzed their travels and struggled to understand their motives and aspirations. The essays selected for this volume, drawn from a range of twentieth-century historians and contextualized in the introduction, provide a comprehensive overview of missionary efforts in Asia, and of the developments in the secular world that both made them possible and encouraged the missionaries’ hopes for success. Three of the studies have been translated from French specially for publication in this volume.