i wanted to know about ABDUL AZIZ AL RAJHI history/background/and about his effort , have any idea???

i wanted to know about his background and about his step by step being one of the biggest billionare/ enterpreneur in the world , from being a money changer on the ground untill becaming the one of the ultimate richest person in the world by opening alrajhi bank,where can i find it , i search in wikipedia ( but there is only story about his sons) and also i search in other web but i didnt find it yet , i appreciate your help??