Ḥusayn-i Qāʾinī, an important early Nizārī Ismaili dāʿī (missionary) who led an uprising against the Saljūqs in Quhistān at the beginning of the Alamūt period. He is sometimes given the title of ‘judge’ (qāḍī) (Rashīd al-Dīn, 107; see also Hodgson, 118). Ḥusayn was a native of Quhistān, situated in the south-eastern part of what is today Khurāsān, and, as indicated by his nisba, hailed from the city of Qāʾin. There is little information about his early life before meeting Ḥasan-i Ṣabbāh, save for the fact that he joined him when he preached secretly in Quhistān.

Ḥusayn-i Qāʾinī became one…