It was, however, nothing less than a reign of terror that inaugurated the new dispensation. On capturing Tabriz in 907/1501, a city two-thirds Sunnite in population, Shah Esmāʿil threatened with death all who might resist the adoption of Shiʿite prayer ritual in the main congregational mosque, and he had Qezelbāš soldiers patrol the congregation to ensure that none raise his voice against the cursing of the first three caliphs, viewed as enemies of the Prophet’s family. In Tabriz and elsewhere, gangs of professional execrators known as the tabarrāʾiān would accost the townsfolk at random, forcing them to curse the objectionable personages on pain of death. Selective killings of prominent Sunnites occurred in a large number of places, notably Qazvin and Isfahan, and in Shiraz and Yazd, outright massacres took place. Sunnite mosques were desecrated, and the tombs of eminent Sunnite scholars destroyed (Aubin, 1970, pp. 237-38; idem, 1988, pp. 94-101).
An integral part of the Safavid imposition of Shiʿism was the eclipsing or suppressing of the Sufi orders, most of them Sunnite in their orientation. As Ebn Karbalāʾi lamented, Shah Esmāʿil “uprooted and eradicated most of the lineages of sayyeds and shaikhs” and “crushed all the selselas [lines of succession], destroying the graves of their ancestors, not to mention what befell their successors” (II, pp. 159, 491). The extirpation of the Kāzaruniya, the oldest Sufi order in Persia existing at the time, was certainly abrupt and thoroughgoing: when Shah Esmāʿil conquered Fars in 909/1503, he desecrated the tomb in Kāzarun of its founder, Abu Esḥāq, and massacred some 4,000 people in its vicinity (Aubin, 1959, p. 58). In general, however, the process was gradual and sporadic, if unmistakable in its tendency; the mid-10th/16th century appears to have been a turning point. Although the Lālaʾi branch of the Kobrawiya to which Ebn al-Karbalāʾi belonged never converted to Shiʿism, one of its members served Shah Esmāʿil as ṣadr (q.v. at iranica.com) before all trace of this hereditary line of shaikhs disappeared.