Answer
Saad bin Saud Al Saud is the grandson of King Abdulaziz, the founder of Saudi Arabia. King Abdulaziz had numerous children, including Saad's father, Saud bin Abdulaziz, who later became King of Saudi Arabia from 1953 to 1964. Therefore, Saad bin Saud Al Saud is the grandson of King Abdulaziz through his father, Saud bin Abdulaziz.