Study of the Governance of Abbasid Rulers in Tabaristan Based on Choronology of Coins and Written Sources

Tabaristan was conquered during Al-Mansour (158-137 AH) after one and a half centuries of resistance to the Arabs. From then on Tabaristan was managed by Abbasid Governors. Our knowledge of the governors of the province is primarily based on historical sources and Arab-Tabaristan coins. Despite the information that is available from Abbasid governors in various sources, determining the precise timing of each and every one of them due to the inconsistency of written texts with numismatic evidences is a challenge for the researchers. The purpose of this research is to answer this question that what are the reasons of the difference between the information extracted from the sources and from the Abbasid coins in Tarbristan? To answer this question, a descriptive-analytical approach has been used. The results of the studies indicate that the political and social turmoil during this period, due to the dissatisfaction of the local people and Ispahbads in the region, as well as the administrative hierarchy of the Abbasids, led to the permanent dismissal and appointment of governors by the Abbasid Caliphs, which could be a reason for incomplete or sometimes mistaken reporting in historical texts. Therefore, coins can be considered as the most important resources and means for establishing the chronology of the rule of Abbasid governors. As the result of present study, in addition to finding an answer to the reasons for the heterogeneity in the chronology of the government of governors, a new and accurate list of the governors in Tabaristan is presented.