Later it was expounded on by various Islamic scholars, such as Ibn Taymiiya in the 13th century, but it did not become institutionalized until the mid-18th century when the theories promulgated by the radical cleric Muhammad ibn Abd al-Wahhab were accepted and imposed as the state religion of his realm by the founder of the House of Saud.
CENTERFORSECURITYPOLICY: Alexiev testifies on Wahhabi influence in US