his study provides a historical-comparative analysis of the dynamics of power and religion in the religious policies of the Buyid and Hamdanid dynasties in relation to the Abbasid Caliphate. The main question of the research is: How did these two dynasties utilize religious elements to legitimize their rule against the dominant power, and what similarities and differences exist in their approaches to religion? The hypothesis of this study suggests that both dynasties, by leveraging Shi'a Islam—particularly through the support of Shi'a scholars and the strengthening of religious institutions—succeeded in reinforcing their political legitimacy against the "dominant other." However, the religious differences (Twelver Shi'a for the Buyids and Ismaili/Zaydi Shi'a for the Hamdanids) and their divergent approaches in confronting the Abbasid Caliphate and other rival forces led to variations in their methods of legitimization. The Buyids, through direct confrontation with the Abbasid Caliphate, managed to diminish its grandeur and align its authority with their own objectives. The comparative historical approach and content analysis of historical and religious sources reveal that while both dynasties used religion to strengthen their political structures, their differing strategies in political and religious interactions distinctly shaped the social structures of their respective regions.