Ḥasan Maḥmūd Kātib (d. after 640/1243) was an Ismaili poet. Born near Qazvīn, he was alive when Imam Ḥasan of Alamūt (d. 561/1166) proclaimed his doctrine ofqiyāmat or spiritual ‘resurrection’ in 559/1164. He was a secretary of the governor of the fortress of Gird Kūh, Shihāb al-Dīn, whom he later followed to Quhistān. Around 630/1232 he was in Alamūt, preparing a copy of the diwan whose surviving fragments are published here, to be offered to the Imam of the Ismailis at the time, ʿAlāʾ al-Dīn Muḥammad (d. 653/1255). Ḥasan Maḥmūd was well-versed in the intellectual and spiritual universe of Nizārī Ismailism as recorded, inter alia, in Naṣīr al-Dīn Ṭūsī’s (d. 672/1274) Rawḍa-yi taslīm Sayr wa sulūk, and Āghāz wa anjām. The present diwan contains the most complete contemporary catalogue of the terminology used in expressing Nizārī Ismaili doctrine, surpassing even the works of Ṭūsī, Nāṣir Khusraw (d. after 462/1070) and Nizārī Quhistānī (d. 720/1320).