Abdulaziz Ibn Saud

Abdulaziz ibn Abdul Rahman Al Saud, often called Ibn Saud, retook Riyadh from a rival dynasty in 1902 and spent three decades conquering and uniting the tribes and regions of the Arabian peninsula. He built his power on an alliance with Wahhabi religious authority and on the Ikhwan, a settled tribal fighting force he later had to crush when it rebelled. In 1932 he proclaimed the Kingdom of Saudi Arabia as an absolute monarchy. His grant of an oil concession to American firms in 1933 opened the era of Saudi oil wealth, and his many sons ruled the kingdom in succession for the rest of the century.