Saudi king's son Mohammed bin Salman is new crown prince
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 been removed from his role as head of domestic security, state media say.
He has pledged allegiance to the new crown prince, his younger cousin.
Why is this significant?
Saudi Arabia has typically been ruled by kings in their 70s or 80s.
Prince Mohammed bin Salman's rapid ascent is seen by the younger generation as a sign that things are changing.
Before his latest promotion, he was responsible for leading Saudi Arabia's war in Yemen, overseeing the kingdom's energy policy and 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, the BBC's Middle East editor Jeremy Bowen reports.
His father King Salman is 81 and reportedly not in the best of health, our correspondent adds.
Prince Mohammed bin Salman could, potentially, lead Saudi Arabia for decades, heralding a long period of internal stability.
However, the new crown prince is close to US President Donald Trump, and could ratchet up pressure against Iran - which would raise tensions in the region.