Saudi Arabian Oil Minister Ali al-Naimi, the architect of the 2014 switch in OPEC policy that’s since roiled the energy market, companies and entire economies from Mexico to Nigeria, is leaving his post.

An 80-year-old who rose from modest Bedouin roots, al-Naimi headed the ministry for almost 21 years, steering the world’s largest crude exporter through wild price swings, regional wars, technological progress and the rise of climate change as a key policy concern.

“During my seven decades in the industry, I’ve seen oil at under $2 a barrel and $147, and much volatility in between,” al-Naimi told a gathering of the who’s who of the American oil industry in February in Houston. “I’ve witnessed gluts and scarcity. I’ve seen multiple booms and busts.”

The departure of al-Naimi, who for years could move markets just by uttering a few words, is the latest sign of how the country’s young Deputy Crown Prince Mohammed bin Salman is stamping his authority over oil policy. Khalid Al-Falih, chairman of Saudi Arabian Oil Co., the state-owned producer, will replace him as minister of energy, industry and mineral resources. Al-Falih is known to be close to King Salman and to Prince Mohammed.

“Khalid has been integral to the current oil policy of Saudi Arabia and has worked very closely with the deputy crown prince,” said Jason Bordoff, director of the Center on Global Energy Policy at Columbia University in New York and a former White House oil official.

While al-Naimi enjoyed a relatively free hand to implement oil policy under King Fahd and King Abdullah, his room for maneuver seemed to have narrowed since last year’s accession to power by King Salman and the growing influence of his 30-something son, Prince Mohammed.

At the April 17 meeting in Doha where producers discussed a possible production freeze to shore up prices, al-Naimi lacked authority to complete a deal, according to his Russian and Venezuelan counterparts. The view of Prince Mohammed, who had insisted that no accord was possible without Iran, eventually prevailed and the talks collapsed.

David Fuller's view

All change as Deputy Crown Prince Mohammed bin Salman ups the stakes in this war of attrition.  Consumers and oil importing countries will be the long-term beneficiaries.