Saudi Arabia’s King Salman bin Abdulaziz named his son and heir Prince Muhammed bin Salman as the kingdom’s prime minister and his second son Prince Khalid as defense minister, a royal decree said on Tuesday.

The reshuffle kept another son, Prince Abdulaziz bin Salman, as energy minister, theroyal decree, carried by state news agency SPA, said.

Foreign Minister Prince Faisal bin Farhan Al Saud, Finance Minister Muhammed al-Jadaan and Investment Minister Khalid al-Falih remained unchanged, the decree showed.

The crown prince, known as MbS, had been the defense minister and has been the de facto ruler of Saudi Arabia, the world’s top oil exporter and a major U.S. ally in the Middle East.

Prince Khalid bin Salman, MbS’s younger brother, previously served as deputy defense minister.

King Salman will still preside the cabinet meetings that he attends, the decree said.

The 86-year-old king, the custodian of Islam’s holiest sites, became ruler in 2015 after spending more than 2-1/2 years as the crown prince. He has been hospitalised several times over the last two years.

Prince Muhammed has changed Saudi Arabia radically since he rose to power in 2017 as he led efforts to diversify the economy from dependence on oil, allowed women to drive and curbed the clerics’ power over society.

His reforms, however, have come with a massive crackdown on dissent, with activists, royals, women rights’ activists and businessmen jailed.

The killing of Saudi journalist Jamal Khashoggi in the kingdom’s consulate in Istanbul in 2018 has tarnished his reputation and strained the kingdom’s relations with the United States and other Western allies.