Abstract With the establishment of the Caliphate foundation and its development in the Abbasid era, Iranians, disappointed with accessing their own political aims through cooperating with the Caliphate, gradually started to reconstruct their kingdom regime and began a competition that somehow had a tough hostility towards Abbasids. The conflicts between the Caliphs and the Kings culminated in the reign of Khwarizmi’s and the power vacuum created by the great Seljuk's’ vanishing caused widespread chaos in the eastern areas of the Islamic empire, from the center of Iran (Persian Iraq). In such a situation, the Abbasids, especially the Caliph al-Nasser, followed the process of recovering the Caliphate political hegemony, while and the Khwarizmi’s, in parallel, were planning a rigid dominance on Islamic world’s eastern regions including Baghdad, the capital of the Caliphate, to restrict its power in religious affairs. Subsequently, these two power centers started to recruit within the local governments. But after several battles between the armies of both sides, Sultan Muhammad Khwarazmshah failed finally. This article attempts to recognize and analyze the motives and causes of the contrast that existed between these two power centers and their subsequent political and military consequences. Historical data were collected from original and reliable sources, and the final research results are explained.
