Muhammad ibn Saud
Muhammad ibn Saud (Arabic: محمد بن سعود ), also known as Ibn Saud, was the emir of Al-Dir’iyyah and is considered the founder of the First Saudi State and the Saud dynasty, which are technically named for his father – Saud ibn Muhammad ibn Migrin.
Ibn Saud’s family (then known as the Al Migrin) traced its descent to the tribe of ‘Anizzah but, despite popular misconceptions,Muhammad ibn Saud was neither a nomadic bedouin nor was he a tribal leader. Rather, he was the chief (emir) of an agricultural settlement near modern-day Riyadh, called Diriyyah. Furthermore, he was a competent and ambitious desert warrior.
Alliance with Muhammad bin Abdul-Wahhab
The initial power base was the town of Ad-Dar’iyah, where he met Muhammad ibn Abdul-Wahhab, who came to Ibn Saud for protection. Muhammad ibn Saud granted this and the two decided to work together to implement Ibn Abdel Wahhab’s ideas of purifying Islam from innovations (heresies) in its practice by bringing it back to its purest form. They formed an alliance in 1744 which was formalized by the wedding of Muhammad bin Abdul-Wahhab’s daughter to Abdul Aziz, son and successor of Ibn Saud. Thereafter, the descendants of Muhammad bin Saud and the descendants of bin Abdul-Wahhab, the Al ash-Sheikh, have remained closely linked.
Using the ideology of Ibn Al-Wahhab, Ibn Saud helped establish the House of Saud among other forces in the Arabian peninsula. The use of religion as a basis for legitimacy differentiated the House of Saud from neighboring clans and built support.
Source : http://en.wikipedia.org/wiki/Muhammad_ibn_Saud