Investigating the reasons for the appointment of Imam Reza for crown prince by Mamun

This paper examines the reasons for the chosing of Imam Reza as a provincial governor by Mamun. The purpose of this research is to identify the personality of Mamun and his performance towards Imam Reza. Mamun was forced to make this appointment not because of Ahle-Beit's friendship and interest in the clan of infallibility and purity family, nor because of his tendency to Shiat (to some scholars) but also in urgency. In order to preserve his rule with clever thinks, Mamun liberated Bani Abbas from the crises created by the Alawians, in commemoration of the Alawians and the crown prince proposal to Imam Reza, in sharp contrast to the caliphs who used to suppress the Alawians. In this paper, the topic of Imam Reza's crown prince has been studied in a descriptiveanalytical manner.