THE CASPIAN PROVINCES

Among the former provinces of the Sāsānian empire, the coastal regions along the southern shore of the Caspian Sea resisted the penetration of the Arabs and Islam most tenaciously. Protected by the lofty Alburz mountain range they escaped the main thrust of the Arab conquering armies as they advanced eastward into Khurāsān. Early Arab invasions were only partially successful. In the year 30/650–1, under the caliph 'Uthmān, Sa'īd b. al-'Āṣ entered Gurgan, the province touching the southeastern coast of the Caspian Sea, and imposed a tribute on its ruler. From there he marched westward to conquer parts of Tabaristān. These conquests were lost again during the struggle between ‘Alī and Mu‘āwiya for the caliphate, and the tribute for Gurgan was frequently withheld. Mu‘āwiya soon after gaining sole possession of the caliphate in 41/661 sent Masqala b. Hubaira to subjugate Tabaristān, but he and his army were annihilated in Rūyān to the west of Tabaristān. In the years 61-4/680–3 an attempt to conquer Tabaristān resulted in a defeat of the Kūfan general Muhammad b. al-Ash‘ath al-Kindī. Gurgān was not brought under Muslim rule until 98/716–17, when Yazīd b. al-Muhallab defeated the Chöl (Ar. Sūl) Turks of the Dihistān steppes north of the Atrak river, who had taken the country from its marzbān Fīrūz b. Qūl, and built the town of Gurgān (near modern Gunbad-i Qābūs) which became the capital of the Muslim province. Yazīd's further attempt to conquer Tabaristān ended in failure, and he was forced to leave the country after concluding a truce.