Although he is still in his youth, Mohammed bin Salman has for a long time held senior government positions and has been at the forefront of the kingdom's plans to wean itself off oil as one of economic strategies that were launched a year ago.
Intent on dispelling speculation of internal divisions in the ruling dynasty, Saudi television was quick to show that the change in succession was amicable and supported by the family.
Prince Mohammed bin Nayef, for years the kingdom's counter-terrorism chief who put down an al Qaeda campaign of bombings in 2003-06, is relieved of all positions, it said.
" PROFESSOR BERNARD HAYKEL, of Princeton University, saying the decision was aimed at avoiding a power struggle". While bin Nayef fell into a diminished role.
Prince Mohammed bin Salman replied: "We will not give up taking your guidance and advice".
"He has a reputation for being aggressive and ambitious", Bruce Riedel, a former Central Intelligence Agency officer who directs the Brookings Intelligence Project in Washington, has said.
Prince bin Salman is also fronting Vision 2030, he plans to diversify the economy away from its dependency on oil, and there must be a new motion with the change in the leadership, she noted. "Prince Mohammed bin Salman is its architect", said Mr John Sfakianakis, director of the Gulf Research Centre.More news: Russia fires missiles from Mediterranean at ISIS in Syria
In an emailed statement in response to questions by Reuters, the ministry said the 5-6 billion riyal cost of the latest step worked out to only about 0.6-0.7 percent of budgeted state spending in 2017 or nearly 0.2 percent of gross domestic product, which could easily be covered by contingency funds.
"We won't wait for the battle to be in Saudi Arabia".
"Some people were predicting that this would lead to a division in the family and strife and some kind of revolt".
Under the same royal decree, King Salman also appointed Prince Abdulaziz Bin Saud Bin Nayef as Saudi Arabia's interior minister.
As reported by the Reuters news agency, his appointment may make Saudi policy more hawkish against arch-rival Iran and other Gulf rivals such as Qatar, increasing volatility in an already unstable region, analysts say.
The article quoted extensively from an analysis by an academic at the London School of Economics, Madawi al-Rasheed, who called the new crown prince's remarks last month about Iran "a statement that ultimately amounts to a declaration of war".