A question that has preoccupied the historiography of race and anti-Blackness is the validity of “race” and “racism” to describe the construction of difference and its deployment to create and enforce social hierarchies before the rise of the Atlantic slave trade. While medieval predecessors of modern racial hierarchy both gave less importance to heritability and allowed greater social mobility to freedmen and their descendants, many of the tropes and stereotypes common to premodern Islamicate depictions of Black people are similar enough to modern racial stereotypes, and the social hierarchy they informed was strong enough, that to describe this social phenomenon as other than racism does more to obfuscate than to nuance. Cecilio Cooper’s concept of the “Black chthonic,” which describes the connection between phenotypic difference and cosmic hierarchy, describes how anti-Blackness can function independently of biological theories of race. In the Kushnameh and Nezami’s Alexander epic, two twelfth-century epics with a strong speculative dimension, Black Africans play small but pivotal roles in the narrative and the development of core themes. In both epics, an episode in which the title character drives Black invaders out of Egypt is positioned as the opening frame for a career of conquest and exploration across a vast region of the world—for Alexander, the world as a whole, for Kush, the Maghreb which includes Africa and Western Europe. In Nezami’s epic, this encounter defines Alexander atop a hierarchy of human and sub-human types. In the Kushnameh, the development of themes of heritability and dynastic lineage complicates notions of genealogical superiority and inferiority, and the significance of Black invaders within the epic’s Neoplatonic and Manichean or Zoroastrian conceptual framework, is more complex. These texts together offer a window into the interaction between phenotypic difference and lineage in medieval Islamicate culture.