BEIRUT, Lebanon — Saudi Arabia installed several new ministers in a series of royal decrees on Saturday, putting allies of the powerful crown prince in key positions to help push forward his efforts to diversify the economy away from oil and to make life more enjoyable for citizens.

The decrees by King Salman, the crown prince’s father, put a businessman in charge of labor policy, a moderate cleric at the helm of the Islamic affairs ministry and a close friend of Crown Prince Mohammed bin Salman at the head of a newly created ministry of culture.

The new culture ministry, which was split off from the Information Ministry, is headed by Prince Bader bin Abdullah bin Farhan Al Saud, who is in his early 30s. The young prince was the mystery buyer of Leonardo da Vinci’s painting “Salvator Mundi,” which sold for a record $450.3 million at auction last year.

American intelligence officials and Arabs familiar with the details of sale said at the time that the real buyer was Crown Prince Mohammed. But Saudi officials provided an alternative story.