ブワイフ朝
Al-Khazin was one of the scientists brought to the court in Ray, Iran by the ruler of the Buyid dynasty, Adhad ad-Dowleh, who ruled from 949 to 983 AD. In 959/960 Khazin was required by the Vizier of Ray, who was appointed by ad-Dowleh, to measure the obliquity of the ecliptic.