Greater Khorasan constituted one of the major civilizational centers of the eastern Islamic world and has consistently attracted the attention of conquerors throughout history. This study aims to examine the process of conversion to Islam in Greater Khorasan from the onset of the Islamic conquests until the end of the fourth Islamic century (tenth century CE). Contrary to simplistic interpretations that attribute the spread of Islam solely to military conquests and the religious policies of Arab rulers, the findings of this research demonstrate that this process was complex, multi-stage, and shaped by the interplay of numerous political, social, cultural, and religious factors. Employing a qualitative methodology grounded in historical content analysis, this study systematically classifies, analyzes, and interprets data drawn from both primary and secondary sources. The findings indicate that Islamization in Khorasan was a gradual process, significantly influenced by factors such as the migration of Arab tribes and Alid descendants (Sādāt), the socio-legal status of non-Arab Muslim converts (mawālī), the religious policies of the Umayyad and Abbasid caliphs, and the approaches adopted by local dynasties—including the Tahirids, Saffarids, and Samanids. Furthermore, cultural interactions between Iranian traditions and Islamic teachings, the presence of diverse religious currents, and the proliferation of scholarly and hadith centers in major urban centers such as Nishapur, Merv, Herat, and Balkh collectively facilitated the gradual and profound acceptance of Islam among the population of Khorasan.
In sum, this research underscores that the Islamization of Khorasan was not merely the outcome of military imposition or top-down governmental policies, but rather the result of a complex, dynamic process of cultural exchange, gradual adaptation, and identity synthesis. Within this process, indigenous Iranian elements and Islamic doctrines interacted dialectically to shape a