In the two centuries after the encounters with Native Americans in Vinland, the alien races that drew the attention of Latin Christendom’s communities were Jews at home in the towns and cities of Europe and Muslims overseas, as we’ve seen in the discussions in Chapters 2 and 3. The thirteenth century, however, saw the arrival of a new alien race at the doorstep of Europe: At Europe’s northern and eastern corridors, steppe peoples whom the Latin West referred to as Tartars adventitiously made an appearance. The arrival of Mongols threw Christendom into disarray, since Mongols materialized as relentless, devastating conquerors, inexorably overrunning all in their path. In the course of half a century, Europeans therefore toiled mightily to render intelligible this new global race, hitherto unknown to them.