During the 13th century CE, the Persian-speaking lands, extending from Central Asia to Iraq were devastated by a series of Mongol invasions. The massive movement of these nomadic warriors from the inner steppes of Asia resulted in the massacre and displacement of many communities, including the Ismaili Muslims of the region. The fall of the chief Ismaili fortress of Alamūt in 1256, followed by the destruction of some two hundred other strongholds, brought to an end the territorial independence of the Ismailis in Persia.

Contrary to belief that the community was virtually eliminated, a small number of Persian Ismailis survived the Mongol onslaught, together with the basic infrastructure of their religious organisation, the daʿwa. After presenting an overview of the development of the Ismaili daʿwa in the historical context, the author explores how this organisation was instrumental in enabling the Persian Ismailis to maintain their religious identity and the cohesion of their community in those difficult times.

Among the various authorities consulted by the author for this study, the most important is the poet Saʿd al-Dīn b. Shams al-Dīn, generally known as Nizāri Quhistānī. Through an analysis of his works, in particular the Safar-nāma (Travelogue) which describes the poet's journey from Quhistān to Transcaucasia around 1280, the author is able for the first time to demonstrate the existence of the Ismaili daʿwa and thus the continuity of Ismaili tradition in Persia through the era of Mongol rule.