"'Abdul-Wahhab did not confine himself to a revolution in words. He also led, in alliance with Ibn Sa'ud, a violent campaign of forced conversion. In 1746... the Saudi-Wahhabi alliance declared jihad against 'the polytheists' [ie, other Muslims in Arabia and beyond]: for them, it was a war of Muslims against pagans... Najd was the first target for conquest. 'Abdul Wahhab did not live to see the conquest of Mecca; he died 12 years earlier, in 1791... The conquest of Hijaz was the most important, but the Saudi-Wahhabi alliance set its sights on the Shi'ites to the north in Iraq. 'Abdul-Wahhab would refer to Shi'ites as rawafid [rejectionists], which remains part of the current terminology in both Wahhabi and al-Qa'idah literature. What transpired in the campaign against the Shi'ites of southern Iraq, especially in the holy city of Karbala', which contains the burial site of Imam Husayn [grandson of the Prophet, and the great martyr of Shi'ism], was nothing short of a massacre. A Wahhabi historian tells the story:
'In the year 1216 [Hijri, 1802], Sa'ud... set out with his divinely supported army and cavalry and nomads from Najd, from the south, from the Hijaz, Tihama and elsewhere. He made for Karbala and began hostilities against the people of Al-Husayn... The Muslims [ie, the Wahhabis] scaled the walls, entered the city by force, and killed the majority of its people in the markets and in their homes. Then they destroyed the dome placed over the grave of Al-Husayn by those who believe in such things. They took over whatever they found inside the dome and its surroundings. They took the grille surrounding the tomb, which was encrusted with emeralds, rubies, and other jewels. They took everything they found in the town: different types of property, weapons, clothing, carpets, gold, silver, precious copies of the Qur'an, as well as much else - more than can be enumerated. They stayed in Karbala for no more than a morning, leaving around midday with all the property they had gathered and having killed about 2,000 people...'
"Thus we learn of 'holy war', Wahhabi style. Other campaigns of plunder, pillage, and mayhem followed. The attack on Mecca and Medina also included the destruction of the gravestones and tombs of close companions and wives of the Prophet. The Ottomans became concerned; the holy sites of Mecca and Medina constituted important sources of legitimacy of the Sultan... by 1819 an Egyptian army, sent to liberate the holy places by order of the Ottoman sultan, landed in Yanbu', and by 1819 the Sauds were defeated - they were pushed out of the Hijaz, and their capital [Dir'iyyah] was sacked... The House of Saud did not settle for defeat. They made various efforts in the 19th century to reclaim their past glory, but internal disputes and interfamily feuds prevented the family from establishing its control over the whole of Arabia or the holy places. That task was undertaken by the founder of the modern kingdom, King 'Abdul-'Aziz." (pp 63-6)