the wahhabi mission has been dominant in most of the central region of najd—its "heartland"—for two hundred years, but in most other parts of the country it has dominated only since 1913-1925. the eastern region has many twelver shias, the southern regions of saudi arabia has many zaydi shias. the hijaz region has long had a more pluralistic tradition. the southwest region of asir is known for its followers of a local leader, idris, revered by many as a sufi saint, a concept which wahhbism opposes. according to one estimate by michael mehrdad izady, "using cultural and not confessional criteria", there are 4.3 million (25%) shia, 4 million (23%) wahhabi, 9 million (52%) non-wahhabi sunnis in saudi arabia two critics of wahhabism (ali al-ahmed and stephen schwartz), also give a relatively high estimate of the non-wahhabi population of saudi arabia—over 60%.