Historians differ on the detail of Abdul Wahhab’s life, but it is widely agreed he was born in the town of al-Uyayna, in the Nejd , in 1703. Tutored by his father in the strict Hanbali school of Islamic jurisprudence, Wahhab studied in Basra in southern Iraq, where debates with Islamic scholars led him to decide reform was needed.
Wahhab’s main theological argument during his lifetime was for a more rigorous, conservative interpretation of Islam, in particular advocating monotheism in line with the Salafi tradition.
Salafis follow early interpretations of Islam from the time of the Prophet Muhammad and his contemporaries, seeing later innovations (such as the veneration of saints by some Sufi sects) as unwelcome and even heretical. Wahhab was able to implement some of his legal interpretations, such as insisting that a woman accused of adultery be stoned, when he returned home in 1740. His followers included the town’s ruler, but his power alarmed other influential local figures and he was eventually banished.
Wahhab was then invited to settle in neighbouring Dirriyah by its ruler, Sheikh Muhammad al-Saud. A pact was made between the two men in which al-Saud promised to put Wahhab’s teachings into practice in return for political support. A marriage between al-Saud’s eldest son and Wahhab’s daughter sealed the union.
To some contemporary Muslim scholars, Wahhab was a pious and respected thinker who encouraged a more literal reading of the Quran. Others thought Wahhab’s views were sharp departures from the mainstream of Islam, and accused him of being fixated with gathering power to himself.
His influence endures today. Both the Saudi justice minister and the country’s Grand Mufti are descended from him, and Saudi Arabia’s legal system remains one of the world’s harshest. Public executions, in places such as Riyadh’s “Chop Chop Square”, are frequent (there were roughly 150 in 2007) and women had no vote in the first nationwide municipal elections in 2005.

http://www.newstatesman.com/middle-east/2009/05/saudi-arabia-wahhab-islamic