This article explores the fashioning of a new discursive realm of Islamic kingship in thirteenth–fourteenth-century Mongol-ruled Iran (the Ilkhanate). It examines how literati, historians, and theologians ingeniously experimented at the Ilkhanid court with Persian and Islamic concepts and titles to translate and elaborate their Mongol patrons’ claims to govern through a unique affinity with heaven. The fusion of Mongol and Islamic elements formulated a new political vocabulary of auspicious, sacred, cosmic, and messianic rulership that Turco-Mongol Muslim courts, starting in the fifteenth century, extensively appropriated and expanded to construct new models of imperial authority. A comparison with Buddhist and Confucian assimilative approaches to the Mongol heaven-derived kingship points to a reciprocal process. Mongol rulers were not simply poured into preset Muslim and Persian molds; symbols and titles were selectively appropriated and refashioned into potent vessels that could convey a vision of Islamic kingship that addressed Chinggisid expectations. From their desire to collect and assume local religious and political traditions that could support and enhance their own legitimizing claims, the Mongols set in motion a process that led to their own integration into the Perso-Islamic world, and also facilitated the emergence of new political theologies that enabled models of divine kingship to inhabit the Islamic monotheistic world.