The Ziyarids, descendants of Ziyar b. Vardanshah, belonged to the Gilite royal clan living in the Dakhil region. Vardanshah is said to have enjoyed great authority among the Gilites. Like other Persian dynasties of the time, they later claimed pre-Islamic royal ancestry alleging that they were descended from Arghush Farhadan, king of Gilan in the time of Kai-Khusrau. Mardavij b. Ziyar in 318/930 was sent by Asfar together with the latter's brother Shirzad to conquer the fortress of Shamiran in Tarum from the Sallarid Muhammad b. Musafir. During the siege he was persuaded to revolt against Asfar by letters from Makan and the Sallarid who both promised him aid. With the help of the sons of the Sallarid he took Shirzad by surprise and killed him together with twenty-nine chiefs of the Varudavand, the tribe of Asfar. As he approached Asfar in Qazvin, the army of the latter went over to him.
Asfar fled, and Mardavij inherited his territories, Ray, Qazvin, Zanjan, Abhar, Qum and Karaj. In 319/931 he captured and killed Asfar and in rapid succession conquered Hamadan, Dinavar and Isfahan from the governors of the caliph. Then he turned against Makan with whom he had at first concluded a treaty after having received his support against Asfar. After an initial defeat, Mardavij in 320/932 took Tabaristan and Gurgan. Makan, whose attempts to recover his territories failed, entered the service of the Samanids. In 321/933 Mardavij, threatened by an offensive of the Samanid Nasr b. Ahmad, agreed to a peace treaty under which he surrendered Gurgan and paid tribute for the possession of Ray to the latter. His attention was now drawn toward the south of his domains where the Buyid 'All, whom he had appointed governor of al-Karaj, had renounced his allegiance and successfully carried out independent conquests. By the end of 322/934 the Ziyarid army had occupied Ahvaz, and cAll, now in Shiraz, again acknowledged his overlordship. Mardavij now was hatching ambitious plans for a campaign to conquer Baghdad and overthrow the caliphate. Then he intended to be crowned in Ctesiphon and to restore the Persian empire. Before he could realize these plans he was murdered in Isfahan in 323/935 by his Turkish troops whom he had gravely insulted.
The Ziyarid cause was further weakened by the defection of the Turks, some of whom joined 'All b. Buy a in Shiraz while others entered the service of the caliph. 'All's brother al-Hasan, the later Rukn al-Daula, thus was able to occupy Isfahan. The majority of the Dailamites and Gilites in the Ziyarid army, however, returned to Ray and pledged allegiance to Vushmgir, the brother of Mardavij. Vushmgir still in 323/935 repulsed Makan and a Samanid army from Tabaristan and conquered Gurgan. Then he acknowledged Samanid overlordship in order to strengthen his rear in resisting the Buyid advance. Evidently with the same motivation he turned over Gurgan to Makan in 325/936. In 328/939-40 Makan was attacked in the main city of Gurgan by the Samanid general Abu 'All b. Muhtaj and expelled after a lengthy siege despite the aid which Vushmgir sent him. Ibn Muhtaj then marched against Vushmgir in Ray and defeated him in a battle which cost Makan his life.
Vushmgir fled to Tabaristan where he was faced with a revolt of al-Hasan b. al-Fairuzan, governor of Sari, who accused him of being responsible for the death of his cousin Makan. Defeated by Vushmgir, al-Hasan joined Ibn Muhtaj and induced him to undertake a new campaign to Tabaristan. Vushmgir was forced to reacknowledge Samanid suzerainty, but as Ibn Muhtaj left for Khurasan he regained Ray, only to be expelled from there in 331/943 by the Buyid al-Hasan, this time for good. He returned to Tabaristan and was defeated there by al-Hasan b. al-Fairuzan who previously had occupied Gurgan. While Vushmgir fled to the Bavandid Ispahbad Shahriyar and then found refuge at the court of the Samanid Nuh b. Nasr, al-Hasan b. al-Fairuzan entered into friendly relations with the Buyid giving him his daughter in marriage, though he prudently acknowledged Samanid suzerainty once more when Ibn Muhtaj re-occupied Ray in 333/945. Vushmgir at this time regained Gurgan with Samanid support but was unable to hold it.
In 335 /947 he again conquered Gurgan and Tabaristan with the help of a large Samanid army and expelled al-Hasan b. al-Fairuzan. In the following year Rukn al-Daula took Tabaristan and Gurgan from him. Al-Hasan b. al-Fairuzan again made common cause with the Buyid. Vushmgir could, however, continue to count on the support of the Samanids in their feud with the Buyids. In the next years Gurgan and Tabaristan changed hands several times until a general peace was concluded between Rukn al-Daula and the Samanids in 344/955 under which the former engaged himself not to molest the Ziyarid in Tabaristan. Numismatic evidence shows that this peace did not last long. In 347/958 Vushmgir succeeded in briefly occupying Rukn al-Daula's capital Ray. Two years later Rukn al-Daula in turn occupied Gurgan for a short time, and in 351/962 (and perhaps in 3 5 5/966) Vushmgir temporarily lost both Tabaristan and Gurgan to the Buyids.
Zaidianism in Medieval Persia
