Book excerpt: Current troubles in the middle east have focused much international attention on Saudi Arabia. However, little has been published in English on the background to its culture and its roots in the First Saudi State that arose in 18th-century Najd (central Arabia).The Islamic reform movement that imbued it with its sense of mission, and the life and thought of its proponent Shaikh Muhammad b. 'Abd al- Wahhab (1703/4-1792), have been similarly neglected. Often referred to outside Arabia as Wahhabism, the Shaikh's teachings have been a fundamental influence on the lives of Saudi Arabians and their government ever since his death in 1792. His ideas continue to inspire his many followers, both inside the Kingdom and abroad. A knowledge of his life and thought is vital to a proper understanding of both Saudi Arabia and the Arab world of today. Students of Saudi Arabian history have long recognized George S. Rentz's thesis on the Shaikh's life and the origins of the First Saudi State as a work of pioneering scholarship. Despite this, since its acceptance in 1947 by the University of California, it has never before now been published. Rentz (1912-87) went on to become head of Aramco's research department. Closely basing his account on the local Najdi chronicles which were contemporary with many of the events they describe, Rentz pieces together the life and thought of the thinker who set out to purify Islam as he saw it practised around him, and to direct Muslims back to the fountainhead of their faith. In the process Rentz tells the colourful story of the creation of the First Saudi State (1745-1818) with its capital at al-Dir'iyah, near present-day Riyadh.