King Salman's decree also means Prince Mohammed bin Salman will become deputy prime minister
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, and the current king's nephew.
Prior to the promotion, the new crown prince was dictating defense and oil policy, including overseeing plans to privatize state oil giant Aramco, within his role.
He also led the war effort in Yemen against rebels, is extremely hostile toward Iran and helped orchestrate Qatar’s isolation in the weeks after US President Donald Trump bolstered ties with Riyadh during a May visit.
State television showed Prince Mohammed kissing the hands of his shafted cousin, portraying a smooth handover and laying to rest concern there might be a power struggle for the throne in the future.
Thirty-one of the 34 members in the Allegiance Council, which decides on matters of succession, voted in favor of the appointment.