Abū Jaʿfar Ustādh Hurmuz, Ibn al-Ḥasan (301–406/914–1015), was a military commander and functionary of the Būyids. Having been a chamberlain (ḥājib) at the court of Būyids for a while, he was called ustādh (Master) (Ibn al-Athīr, 9/224). Nothing is known of his childhood and youth. According to Ibn al-Athīr (9/224), he was chamberlain during the reign of the Būyid ʿAḍud al-Dawla Fannā-Khusraw (r. 324–372/936–982). When ʿAḍud al-Dawla died, there was a contest between his sons Sharaf al-Dawla and Ṣamṣām al-Dawla over the succes…