Muhammad Ibn Abd al-Wahhab (1703-1792) joined forces in 1744 with a tribal chief, Muhammad Ibn Saud, to lead a militant reform movement in the Arabia peninsula. Although known to us today as the "Wahhabi" movement, they called themselves Muwahidun: "those who advocate oneness," i.e. strict monotheists according to the Islamic doctrine of Tawhid, which Abd al-Wahhab understood not merely as the "oneness" of God, but, the exclusiveness of the One God. Adherents of the movement also called themselves followers of al-salaf ("the predecessors"), a reference to the early companions of the Prophet Muhammad.
Influenced by the thought of medieval theologian Ibn Taymiyya, the Wahhabis practice a form of legalism somewhat resembling the Hanbali School of jurisprudence. An innovation of theirs, however, is the exclusion of the normal Islamic practice of ijma ("consensus") as the basis of Islamic Sharia law.
The Wahhabis have mostly been unapologetic Sunni supremacists. In the eighteenth and nineteenth centuries, they embarked upon an uncompromising campaign against Sufis, Shiites, and all others deemed unfaithful to the Wahhabis' austere interpretation of the sunna ("custom") of the Prophet Muhammad. The seventh century ways of Muhammad and his community at Medina constituted the only acceptable models for Wahhabis, and, all Muslims, in their view, should be compelled to follow these practices. The practices of many Muslims who came after the Prophet were labeled bida'a, "objectionable innovations." At first, these included the building of minarets (acceptable to Wahhabis today) and the use of funeral markers. Wahhabi zealots even tried to destroy the tomb of the Prophet in Medina and were narrowly prevented from doing so through the intervention of King Abd al-Aziz al-Saud. Religious police, called mutawi'oon ("enforcers of obedience") were responsible for maintaining Wahhabi moral order. In recent times, Wahhabi standards have moderated somewhat from what they once were, but the mutawi'oon remained a pillar of the religious Saudi establishment in the twentieth and early twenty-first centuries.
Ibn Abd al-Wahhab labeled all who disagreed with him heretics and apostates, which in his eyes justified the use of force in imposing both his beliefs and his political authority upon neighboring tribes. This in turn led him to declare holy war (jihad) on other Muslims (neighboring Arab tribes), an act that would otherwise have been legally impossible under the rules of jihad.
In 1802, the Wahhabis captured the holy Shiite city of Karbala in Iraq and destroyed the tomb of the Shiite Imam Husayn. In 1803 the Wahhabis captured Mecca. The Ottoman Turks became alarmed and dispatched Muhammad Ali, the Ottoman ruler of Egypt, to challenge the Wahhabis in 1811. He succeeded in reimposing Ottoman sovereignty in 1813. Nearly a century later in 1901 with Wahhabi help, Saudi amir Abd al-Aziz al-Saud recaptured Riyadh. Saud's sovereignty over the Arabian peninsula grew steadily until 1924 when his dominance became secure. The Wahhabis went on a rampage throughout the peninsula at this time smashing the tombs of Muslim saints and imams, including the tomb of the Prophet's daughter Fatima (see Wahhabi raid of 1924). Saudi Arabia was officially constituted as a kingdom in 1932.
The first Wahhabi missionaries to Central Asia arrived there in 1912 led by a resident of Medina named Sayed Shari Muhammad. They set up cells in the Fergana Valley and Tashkent. (more on radical movements in Uzbekistan) But, the big impetus for Wahhabi mission activity came in 1962 when the Muslim World League was founded in Saudi Arabia for the specific purpose of exporting Wahhabism throughout the world (see Gilles Kepel, Jihad: The Trail of Political Islam (Cambridge, MA: Belknap Press, 2002), 52). After this time, Wahhabism began to fall under the influence of even more extreme ideas as exiled radicals from the Palestinian territories and Egypt found their way to the Saudi kingdom. Some (Abdullah Azzam and Muhammad Qutb, brother of Sayyid Qutb, whom the Egyptians executed in 1966) began teaching in Saudi universities and laid the foundations for the sahwa ("awakening") movement that took hold in the 1980s. The sahwa movement was based on a blend of Wahhabist ideas and those of Sayyid Qutb and contributed to such events as the Buraydah Uprising (1994).
The surge in oil prices following the 1973 Arab-Israeli war that brought unprecedented high levels of wealth into Saudi Arabia meant huge amounts of money became available to fund these Wahhabi missionary movements. The Wahhabis began supporting Islamist revivalist movements in places like Egypt, Pakistan, Malaysia, Indonesia, Western China, East Africa, and Central Asia. Wahhabi translations of the sayings of Ibn Taymiyya were distributed in Egypt and used by extremist members of the Jihad organization there to justify the assassination of President Anwar Sadat in 1981 (see Gilles Kepel, Jihad: The Trail of Political Islam (Cambridge, MA: Belknap Press, 2002), 72 and 86f.). Wahhabi dissidents seized and briefly held the Great Mosque in Mecca in 1979.
In the 1990s, in the aftermath of the war to liberate Kuwait, the Saudi government invited the United States to build military bases and station troops in the kingdom. As a result, tensions between the ruling Saudis and their Wahhabi allies began to grow. The Buraydah Uprising (1994) made it clear to the Saudis that Wahhabi fundamentalism had grown to become a potent threat to their sovereignty. Arguably the most famous Wahhabi Muslim of the late 20th and early 21st centuries was Osama bin Laden.