On 11 May 1933, he was appointed Crown Prince by his father. When Abdulaziz appointed him as heir to the throne, his advice to his son was that he should always be devoted to spreading Islam, strive hard to look after the concerns and affairs of his subjects and be truthful in word and deed. He also advised Saud to respect Muslim scholars, and keep their company and listen to their advice. The young Saud then pledged to his father that he would loyally abide by his words. The following year, Abdulaziz sent two military expeditions; one of them was led by Crown Prince Saud, who regained Najran and advanced secretly through the rugged mountains in the northwest part of Yemen.