Conjunctionalism sits at the intersection of premodern science, history, and belief. Early medieval writers like Mashallah ibn Athari used the theory to formulate a universalist history which situated the rise of Islam and the subsequent Abbasid empire as the legitimate inheritor of the past. Pre-Islamic history was drawn into a religious narrative and granted scientific explanation as part of imperial ideology. Abbasid caliphs promoted and elevated prognostications by al-Kindi and Abu Ma’shar to project a sense of stability and endurance. In the 9th and 10th century, the Abbasid caliphate faced a series of rebellions and direct threats to their legitimacy; rebels seized trade routes, disrupted the Hajj pilgrimage, and sacked Mecca. This paper will examine how conjunctionalism became a site of contestation formed within the context of the rise of heretical religious rebellions and the methods by which Abbasid sympathizers formulated a world history which rejected the legitimacy of rival claimants. Through a contextual reading of al-Kindi and al-Biruni this paper will situate conjunctionalism and the arguments of Abbasid legitimacy as discursive strategies unpacking the political anxieties the dynasty. Rejecting the apocalyptic fervor of the uprisings, the Abbasids would lean on conjunctionalism to explain the political and historical climate while projecting a sense of continuity and stability. This paper will provide an intervention into the early history of Islamic science and its role in empire-building.