By the late 11th century, the Shi'a sub-sect of Ismailism (later Nizari Ismailism) had found many adherents in Persia, although the region was occupied by the Sunni Seljuk Empire. The hostile tendencies of the Abbasid–Seljuk order triggered a revolt by Ismailis in Persia under Hassan-i Sabbah. Due to the increasingly significant socio-economic issues, the decentralization of the Seljuk government leading to inefficient army mobilization, and a unifying factor of religion in the provinces facilitating the swift spread of the revolt, the Seljuks were unable to quickly put down the revolt.