Historical Background of Islamic Conquests in Iran: The Collapse of Sasanian Political Order according to Written Sources and the Numismatic Evidence

Islamic conquests in Iran took place at the beginning of the reign of Yazdgerd III 632-651 A.D. occupying most of the parts in less than a decade revealed that the Sasanid government had lost its previous military and defensive power. The historical texts of the early Islamic centuries which were highly referred to by the contemporary historians proved this hypothesis as well. These texts mentioned about a turbulent period beginning with the death of Khosrow II (590-628 A.D.) during which several kings and queens reigned in a short while. However, these sources did not mention about the Sasanids political power as well as the limits of their geographical territory. It is necessary to note that these issues were clearly reflected in the coins of that era which were not referred to and somehow neglected. The numismatic evidence and its comparison with the written sources in the present work revealed that the kings of that era who were reigning for a short while and most often were governing several states at the same time, were not able to stabilize their political and military power due to the limitations in human and financial resources. When Yazgerd III became the king which was contemporary with the Muslims’ conquests, the Sasanid government had lost its political authority and economic power long time ago and was at the state of decline and collapse.