al-Mu'ayyad fi'l-Din al-Shirazi

Al-Mu'ayyad fi'l-Din al-Shirazi (full name Abu Nasr Hibat Allah ibn Musa al-Shirazi) was an Ismaili Shia scholar, poet and statesman who rose to lead the Fatimid da'wa — the empire's "religious mission" or network of missionaries that spread the Ismaili interpretation of Islam. Born in Shiraz in the Persian province of Fars around 1000 CE, he inherited his father's post as the local da'i (missionary). His own memoir, the Sira al-Mu'ayyadiyya — the chief source for his life and an unusually personal autobiography for its age — recounts how he won the favour of the Buyid ruler Abu Kalijar before pressure from the Sunni Abbasid caliphate in Baghdad forced him into exile, first to nearby Ahvaz and finally abroad. After years of travel he reached the Fatimid capital, Cairo, around 1045-46. There he served the Imam-caliph al-Mustansir for decades, eventually attaining the highest rank, da'i al-du'at (chief missionary), and directing the academy and mission headquarters, the Dar al-'Ilm. In 1056 he was sent, reportedly reluctantly given his age, on a diplomatic mission to Syria, coordinating the pro-Fatimid campaign of the general al-Basasiri that briefly placed Baghdad under Fatimid allegiance. He is remembered as the teacher of the famous poet-traveller Nasir Khusraw and as founder of a tradition of da'wa poetry. His 800 lectures, the al-Majalis al-Mu'ayyadiyya, remain a major Ismaili source. He died in Cairo in 1078 and was buried in the Dar al-'Ilm.