An Analysis of the Process of Minting the Phrase, "Ali Waliullah" on the Coins of the Bavandians of Kayusiyya

The Bavandian dynasty is one of the most important dynasties ruling Tabarestan. They ruled for more than seven centuries at their headquarters in Shahriarkuh. During this period, this dynasty was divided into the branches of Kayusiyya, Ispahbadhiyya and Kinkhwariyya. One of the most important actions of the first branch of the Bavandians, i.e. Kayusiyya, was the minting of the phrase "Ali Waliullah" on their coins. Therefore, the main issue in this study is to investigate the causes and factors of multiplication of the phrase "Ali Waliullah" on the Bavandian coins. In this research, using historical sources and numismatic studies and relying on descriptive-analytical method, the multiplication of the phrase "Ali Waliullah" on the Bavandian coins has been studied and analyzed. The results of the research indicate that the themes of Rostam ibn Shervin and Marzban ibn Rostam coins have been set in two directions in order to legitimize the government. On the one hand, the phrase "Ali Waliullah" and on the other hand, the name of the Abbasid Caliph are inserted. We can speak of two legitimizing currents: 1) Gaining legitimacy from outside the Bavandians realm. 2) Gaining legitimacy within the territory of Bavandians. In this way, the coins present a legitimate image of Rostam ibn Shervin which is in line with the beliefs of the people. They also seek the legitimacy from the sides of the Abbasid Caliph and the Amir of the Buyid.