Understanding the role and function of rulers’ religious policies and their outcomes opens up new horizons in historical research that adopts social and cultural perspectives. Although the Afsharid era was a brief and transitory period in Iran’s history, it is considered a notable epoch due to the unprecedented religious endeavors and measures undertaken by Nader Shah. Despite the considerable research on various aspects of Nader Shah’s reign, what has remained unaddressed—or at least not examined in an independent and scholarly manner—is the study and analysis of the background, reasons, aims, and motivations behind his religious policy and the concept of Islamic unity.

Using a descriptive-analytical approach and drawing on library and documentary sources, this study investigates the various facets of Nader’s religious policy. The findings indicate that, by proposing and implementing the theory of Islamic unity, Nader Shah sought both to gain legitimacy and to generate and regenerate public consent for himself across the Islamic world. Politically motivated, he applied the principle of Islamic unity in his dealings with Sunnis within Iran and in his relations with other Muslim states, particularly the Ottoman Empire—an important step toward Islamic solidarity. However, in the end, due to the specific historical circumstances of the period and especially the lack of support from Ottoman scholars, this policy did not succeed.