The Mongol advance into the lands of Islam in the time of Chinggis Khan was regarded by Muslims as a catastrophic event. Not only did it inflict pain and suffering on untold numbers of people while also destroying much of the infrastructure of the eastern Islamic world, it also represented an incursion of non-Muslims deep into lands considered core to the history and identity of medieval Islam. The source for this option is by a contemporary Arab writer Ibn al-Athir, who, while not an eyewitness, knew of these events from refugees who made their way to Syria where he was active. In this paper, consider how Ibn al-Athir tried to make sense of the “Tatars” (as he called the Mongols) in a broader context of Islamic culture and history. To what causes does he ascribe the success of Chinggis (here rendered as Chingiz)? Whom does he blame?