ZEYARID DYNASTY

also spelled Ziyarid (927c. 1090), Iranian dynasty that ruled in the Caspian provinces of Gurgan and Mazandaran. The founder of the dynasty was Mardaviz ebn Zeyar (reigned 927935), who took advantage of a rebellion in the Samanid army of Iran to seize power in northern Iran. He soon expanded his domains and captured the cities of Hamadan and Esfahan. Mardaviz was murdered in 935, and Zeyarid power thereupon disintegrated. During subsequent hostilities between the Samanid and the Buyid dynasties, the Zeyarids changed their allegiance several times and thus were able to maintain their autonomy. But with the consolidation of Ghaznavid power, the Zeyarids acknowledged that dynasty's suzerainty and entered into various marriage alliances with it. When the Seljuqs occupied Mazandaran in the mid-11th century, the Zeyarids were forced to withdraw into the mountainous territory on the southern Caspian shores, where they ruled until about 1090. The Zeyarids were distinguished patrons of the arts. The noted Islamic geographer and scientist al-Biruni resided for many years at the court of Qabus I ebn Voshmagir (reigned 9781012). Keykavus (reigned 104990) himself was the author of a famous manual for princely behaviour, the Qabus-nameh (Mirror for Princes).