For most of the period between his death and the nineteenth century Ibn Taymiyya was a respected but peripheral figure, read within the Hanbali school and largely set aside elsewhere. The Ottoman religious establishment worked in the Hanafi school and in Ashari theology, both of which he had written against.
Two things changed that. The movement founded by Muhammad ibn Abd al-Wahhab in the Arabian interior in the eighteenth century took his rulings on tombs and on associating partners with God as its authority. And from the later nineteenth century the printing press put his works into wide circulation for the first time, with reformist editors in Cairo and elsewhere issuing them to readers who had never had access to the manuscripts.
Twentieth century movements then drew on him in incompatible directions. Reformists cited his insistence on returning to the earliest generations against what they regarded as inherited accretion. Militant groups cited his rulings on the Mongols to justify fighting governments that call themselves Muslim.
That last use has been challenged on textual grounds. At a conference held at Mardin in 2010, participants examined the manuscript of the ruling associated with the town and argued that the printed editions carry a reading that reverses its sense, turning an instruction about how a population should be treated into an instruction that it be fought. The argument is about a single word, and it has not settled the wider dispute, but it illustrates the position he now occupies: a thirteenth century jurist whose sentences are contested in the present tense, by people who agree on very little except that he matters.