He reconquered his family's ancestral home city of Riyadh in 1902. This started 30 years which made him the ruler of nearly all of central Arabia. He consolidated his control over the Najd in 1922, then conquered the Hijaz in 1925. He united his dominions into the Kingdom of Saudi Arabia in 1932. As King, he presided over the discovery of petroleum in Saudi Arabia in 1938 and the beginning of large-scale oil production after World War II. He fathered many children, including 45 sons. He died of a heart attack. All the later kings of Saudi Arabia have been his children.