Saudi Arabia's King Salman bin Abdulaziz named his son and heir, Prince Mohammed bin Salman, as the Kingdom's Prime Minister and his second son, Prince Khalid as Defence Minister, a Royal Decree said on Tuesday, Reuters reports.
The reshuffle kept another son, Prince Abdulaziz bin Salman, as Energy Minister, the Royal Decree, carried by state news agency, SPA, said.
Foreign Minister, Prince Faisal bin Farhan Al Saud, Finance Minister Mohammed Al-Jadaan and Investment Minister, Khalid Al-Falih remained unchanged, the Decree showed.
The Crown Prince, known as MbS, had been the Defence Minister and has been the de facto ruler of Saudi Arabia, the world's top oil exporter and a major US ally in the Middle East.
Prince Khalid bin Salman, MbS's younger brother, previously served as deputy Defence Minister.
King Salman will still preside over 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 Mohammed 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.