poet, theologian, and religious propagandist, one of the greatest writers in Persian literature.

Nāṣir-i Khusraw came of a family of government officials who belonged to the Shīʿite sect of Islām, and he attended school for only a short while. In 1045 he went on a pilgrimage to Mecca and continued his journey to Palestine and then to Egypt, which was ruled at that time by the Fāṭimid dynasty. The Fāṭimids headed the Ismāʿīlīyah sect, an offshoot of Shīʿite Islām, and they were engaged in propagating that doctrine by missionaries throughout the Islāmic world. Nāṣir-i Khusraw became such a missionary, though it is not certain whether he became an Ismāʿīlī before his trip to the Fāṭimid capital or after. He returned to his homeland in what is now Afghanistan, but his vigorous advocacy of the Ismāʿīlīyah ideology within Sunnīte territory forced him to flee to Badakhshān, where he spent the rest of his days, lamenting in his poetry that he was unable to be an active missionary.

Nāṣir-i Khusraw's poetry is of a didactic and devotional character and consists mainly of long odes that are considered to be of high literary quality. His philosophical poetry includes the Rawshana'ināme (Book of Lights). Nāṣir's most celebrated prose work is the Safarnāme (Diary of a Journey Through Syria and Palestine), a diary describing his seven-year journey. It is a valuable record of the scenes and events that he witnessed. He also wrote more than a dozen treatises expounding the doctrines of the Ismāʿīlīs, among them the Jāmiʿ al-ḥikmatayn (“Union of the Two Wisdoms”), in which he attempted to harmonize Ismāʿīlī theology and Greek philosophy. Nāṣir's literary style is straightforward and vigorous. In his verse he displays great technical virtuosity, while his prose is remarkable for the richness of its philosophical vocabulary.