Saudi Arabia’s king has appointed his son Mohammed bin Salman as crown prince – replacing his nephew, Mohammed bin Nayef, as first in line to the throne.
King Salman’s decree also means Prince Mohammed bin Salman, 31, will become deputy prime minister while continuing as defence minister.
Prince Mohammed bin Nayef, 57, has also been removed from his role as head of domestic security, state media say.
He has pledged allegiance to the new crown prince, news agency SPA reports.
King Salman, 81, acceded to the throne in January 2015 after the death of his half-brother Abdullah bin Abdul Aziz.
Saudi Arabia has typically been ruled by kings in their 70s or 80s.
Prince Mohammed bin Salman’s latest promotion, and his rapid ascent, is seen by the younger generation as a sign that things are changing.
Analysis by Jeremy Bowen, BBC Middle East editor
This is a big shakeup in the succession.
The deposed heir to the throne, Mohammed bin Nayef, is a widely respected prince who was in charge of the fight against al-Qaeda sympathisers in Saudi Arabia. He’s lost his job as interior minister as well as his position as crown prince.
The new heir to the Saudi throne, Prince Mohammed bin Salman, has carved out a much higher profile than Prince Mohammed bin Nayef. His father King Salman is 81 and reportedly not in the best of health.
Prince Mohammed bin Salman was already defence minister and in charge of economic reform. He must have already ruffled a lot of feathers in a royal family that was used to being presided over by a succession of elderly men.
So far his most controversial move has been to run Saudi Arabia’s war in Yemen. The Saudi campaign has been criticised for human rights violations – including killing many civilians,