al-Shahrastānī was a theologian and historian from northern Khurasan active in the 12th century. He was born in Shahristān, as his nisba suggests, in the late 11th century. He moved to Nishapur where he was trained by several disciples of the Ashʿarite theologian al-Juwaynī (d. 1085). He studied Ashʿarī kalām with Abū’l-Qāsim al-Anṣārī (d. 1118) and hadith with Abū’l-Ḥasan al-Madīnī (d. 1100). Meanwhile, he also trained in Shāfiʿī jurisprudence with the qāḍī of Tus and friend of al-Ghazālī, Abū’l Muẓaffar al-Khwāfī (d. 1106) as well as Abū Naṣr al-Qushayrī (d. 1120). There is some debate as to his own theological beliefs, with some believing he was an Ashʿarite himself, while others claiming rather that he was an Ismāʿīlī practicing taqiyya (religious dissimulation). In 1117 he undertook the pilgrimage to Mecca, and on his return stopped in Baghdad. There he got a job teaching and preaching at the Niẓāmiyya madrasa thanks to the support of a friend, Abū’l-Fatḥ al-Mayhanī (d. 1129). He remained in this role until 1120, when he returned to Khurasan. al-Shahrastānī was employed as a deputy (nāʿib) in the chancellery by the vizier Naṣīr al-Dīn al-Marwazī (d. 1131) under the Seljuq ruler Sanjar (r. 1118-1157). He established a good relationship with Sanjar, before eventually returning to his hometown of Shahristān, where he died in 1153. He wrote twenty or more works which are extant on theology, heresy, philosophy and other topics.