The Crown Prince of Saudi Arabia Mohammed bin Salman (MBS) has been named prime minister, a post traditionally held by the king, in a government shuffle announced Tuesday.
MBS, who has already been the kingdom's de facto ruler for several years, previously served as deputy prime minister under King Salman as well as defense minister.
He is being replaced as defense minister by his younger brother, Khalid bin Salman, who was deputy defense minister.
The heads of other critical ministries, including interior, foreign and energy, remained in place, according to a royal decree from King Salman published by the official Saudi Press Agency.
The crown prince, who turned 37 last month, has been first in line to succeed his father as king since 2017.
Saudi Arabia has for years sought to quell speculation over the health of the 86-year-old king, who has ruled the world's top oil exporter since 2015.
In 2017, it dismissed reports and mounting speculation that the king was planning to abdicate in favor of MBS.
King Salman has been hospitalized twice this year, most recently a one-week stay in May that involved tests including a colonoscopy, according to state media.
The crown prince became defense minister in 2015, a key step in a swift consolidation of power.
In that role, he has overseen Saudi Arabia's military activities in Yemen, where the kingdom leads a coalition backing the internationally recognized government in its fight against Iran-aligned Houthis.
He has also become the public face of a sweeping reform agenda known as Vision 2030.
Changes have included granting women the right to drive, opening cinemas, welcoming foreign tourists, defanging the religious police and hosting pop stars and high-profile heavyweight fights and other sporting events.
Yet, he has also jailed critics and, in a sweeping purge of the nation's elite, detained and threatened some 200 princes and businesspeople in Riyadh's Ritz-Carlton hotel in a 2017 anti-corruption crackdown that tightened his grip on power.
He gained global notoriety for the 2018 killing of dissident Saudi journalist Jamal Khashoggi in the kingdom's Istanbul Consulate.
Last year, U.S. President Joe Biden declassified an intelligence report that found MBS had approved the operation against Khashoggi, an assertion Saudi authorities deny.
But the spike in energy prices triggered by Russia's invasion of Ukraine spurred a number of Western leaders to travel to Saudi Arabia to appeal for ramped-up oil production, notably then-U.K. Prime Minister Boris Johnson and Biden himself, who swallowed an earlier vow to make the Saudi leadership a "pariah."
German Chancellor Olaf Scholz became the latest major leader to visit the kingdom this past weekend.
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.