The author proposes, first, a comparative analysis between the data conveyed, on the first hand, by pre-modern traditions on Nasir-i Khursaw, and on the second hand by historical literature of different periods, in order to reconstruct the biography of the tenth-century propagator of the Isma‘iliyya in the Pamir. He then switches to oral traditions of the Tajikistani Autonomous Region of Higher Badakhshan: Contrary to the prevailing denegation of the Soviet period, T.S.K. broaches this material (collected between 1998 and 2002) as a significant genre of popular poetic creation, and shortly tries to stress its specificity (through elliptical comparisons with other religious traditions, Orthodox Christian in particular). His main contribution is a general hypothesis on the sanctification of derogatory judgements between inhabitants of different villages and valleys of the Pamir, through allusions to their respective alleged attitudes (often negative) toward Nasir during the latter’s missionary activity. So doing, the author provides a telling illustration of the role of hagiography, reinvented through vernacular oral tradition, in the founding of communal identity in a peripheral region of the world of Islam.