Following the Mongol invasion of Iran in 616 (AH) and the death of Sultan Mohammad Khwarazm Shah in 617 (AH), a period of political competition for power began and various parts of Iran were influenced by the local governments. The interval between the Mongol invasion and the fall of Baghdad was a difficult time for Iranian local governments to resolve the crisis of legitimacy and sovereignty. The linking with the remnants of Kharazmshahi monarchy, the Abbasid caliphate, and the central Mongol court were the most important aspects of their political struggle. One of the most important foundations of the legitimacy of local governments was the approval of the Abbasid caliph within the framework of Islamic caliphate theory. The main issue of this article is to examine the relationship of local governments with the institution of caliphate after the Mongol invasion and how these relations are regulated and changed in encountering the Mongols, in order to maintain the legitimacy and continuity of sovereignty. This descriptive and analytical study, based on library resources, revealed that the Mongol invasion and their increasing threats gradually changed the process of legitimizing local governments from the caliphate.