Closer ties between Saudi Arabia and US President Donald Trump's administration helped pave the way for a succession shake-up making a 31-year-old prince the kingdom's de facto ruler, analysts say.
King Salman, 81, on Wednesday, named his son Mohammed bin Salman crown prince and heir to the throne after firing Mohammed bin Nayef, whose counter-terrorism expertise had made him a favourite of previous American administrations.
Over the past two years Mohammed bin Salman accumulated vast powers at the expense of Mohammed bin Nayef, 57, a veteran law enforcer who served as both crown prince and interior minister.
Mohammed bin Salman chipped away at his authority but Mohammed bin Nayef's popularity with the previous US administration of Barack Obama had prevented his ouster, said Stephane Lacroix, associate professor at Sciences Po university in Paris.
"This all changed when Trump came to power," he said.
After assuming office in January, Trump made it clear that his Middle East partners are Mohammed bin Salman, Abu Dhabi crown prince Sheikh Mohammed bin Zayed al-Nahyan and Egyptian president Abdul Fattah al-Sisi, Lacroix said. Riyadh welcomed Trump's more aggressive attitude towards its rival Iran, which Saudi Arabia accuses of interference throughout the region.
Mohammed bin Salman was an early visitor to Washington, where he met Trump in March before the president last month made the first overseas trip of his presidency to Saudi Arabia. Trump received a royal welcome from Mohammed bin Salman and others.