Ibn Taymiyya's three unprecedented fatwas (legal verdicts) that excommunicated the Ilkhanid authorities and their supporters as apostates over their neglect to govern by Sharia (Islamic law) and preference of the traditional Mongol imperial code of Yassa; would form the theological basis of 20th century Islamist and Jihadist scholars and ideologues. Reviving Ibn Taymiyya's fatwas during the late 20th-century, Jihadist ideologues like Sayyid Qutb, Abd al-Salam al-Faraj, Abdullah Azzam, Usama bin Laden, Ayman al-Zawahiri, etc. made public Takfir (excommunication) of contemporary governments of the Muslim world and called for their revolutionary overthrowal through armed Jihad.
