It is well-known that medieval Muslim scholars such as Ibn Sīnā and Ibn Khaldūn used theories of climate and environment to racialize black Africans, referred to collectively as the Sūdān. In discussions of this intellectual tradition, it is also frequently noted that comparisons between the people of the far south and the far north were used to illustrate their ugliness and barbarity, directly linking those qualities to the extreme climates in which they lived. Previous analyses of these comparisons have focused on textual themes such as silent trade; human sacrifice and cannibalism; lack of written language and law; and a set of distinctive, negatively-perceived physical traits such as dark skin and blue eyes. In my paper, I will trace the evolution of a new theme that appeared in the thirteenth century: comparison between the Tatar/Mongol invasion of the central Islamic lands and attacks by the Damādim on various kingdoms of the Sūdān. This theme seems to have been introduced for the first time by Ibn Saʿīd in his Kitab al-Jughāfiyā, composed sometime between 658/1269 and 685/1286-7 in Tunis. Ibn Saʿīd compared the Tatar conquest of Persia with an attack by the Damādim on the kingdoms of Nubia and Ethiopia in East Africa. Ibn Khaldūn incorporated this comparison into his universal history, the Kitāb al-ʿIbar, in the late fourteenth century. However, in the early fourteenth century, the Mamluk official al-ʿUmarī took the comparison in a different direction, placing it in the mouth of Mansa Musa, the famous ruler of Mali in West Africa. According to al-ʿUmarī, Mansa Musa claimed an enemy among the Sūdān comparable to the Tatars as the enemy of the Mamluks, and al-ʿUmarī connected Mansa Musa’s description of this enemy with Ibn Saʿīd’s description of the Damādim. Al-ʿUmarī’s decision to borrow this theme represents a leap both geographically, from East to West Africa, and conceptually, from barbarians preying on black Christians to worthy adversaries for the defenders of Islam. Why did he make this leap? I will argue that al-ʿUmarī’s decision to rework Ibn Saʿīd’s comparison fits a pattern identified by Michael Gomez in his recent book African Dominion: it bolsters Mansa Musa’s portrayal as a Muslim ruler on a global, rather than a regional, scale. I will also examine how the Tatar-Damādim comparison reflects racialized characterizations of the rulership of both Mansa Musa and the Mamluks.