Wahhabism ( Arabic : الوهابية , al-Wahhābiya(h) ) is an Islamic doctrine and religious movement founded by Muhammad ibn Abd al-Wahhab.  It has been variously described as "ultraconservative",  "austere",  "fundamentalist",  or "puritan(ical)";   as an Islamic "reform movement" to restore "pure monotheistic worship" ( tawhid ) by devotees;  and as a "deviant sectarian movement",  "vile sect"  and a distortion of Islam by its opponents.   The term Wahhabi(ism) is often used polemically and adherents commonly reject its use, preferring to be called Salafi or muwahhid.    The movement emphasises the principle of tawhid  (the "uniqueness" and "unity" of God ).  It claims its principal influences to be Ahmad ibn Hanbal (780–855) and Ibn Taymiyyah (1263–1328), both belonging to the Hanbali school,  although the extent of their actual influence upon the tenets of the movement has been contested.  
Wahhabism is named after an eighteenth-century preacher and activist, Muhammad ibn Abd al-Wahhab (1703–1792).  He started a reform movement in the remote, sparsely populated region of Najd ,  advocating a purging of such widespread Sunni practices as the veneration of saints , the seeking of their intercession , and the visiting of their tombs , all of which were practiced all over the Islamic world, but which he considered idolatry ( shirk ), impurities and innovations in Islam ( Bid'ah ).   Eventually he formed a pact with a local leader Muhammad bin Saud offering political obedience and promising that protection and propagation of the Wahhabi movement mean "power and glory" and rule of "lands and men."