Saudi Arabia's young Crown Prince Mohammed bin Salman has taken his riskiest gamble yet with the stunning arrests of top princes, military officers, government officials and influential businessmen in the kingdom.
The sweep, which the government says is aimed at eliminating corruption, also appears to be aimed at stamping out potential rivals or critics of Prince Mohammed, popularly known as "MBS" and the son of King Salman.
The move is raising concerns over increasing totalitarianism along with disarray and resentment from within a royal family whose unity has been the bedrock of the kingdom.
Most stunning in the arrests of 11 princes and 38 officials and businessmen are the detentions of two sons of the late King Abdullah. Until Saturday, Prince Miteb bin Abdullah had headed the powerful National Guard; Prince Turki bin Abdullah was once governor of the capital, Riyadh.
The two — both cousins of the crown prince — were considered the favorites of King Abdullah, who ruled until his death in January 2015, when his half brother King Salman was crowned monarch.
Prince Miteb's role as head of the National Guard for the past four years was symbolic and strategic, a historic pillar of how power had been distributed in the House of Saud.
As the throne passed from brother to brother, security posts were passed from father to son. The system was meant to disburse the levers of power among the various branches of the ruling family, although ultimate decision-making rests with the king.
King Salman had once been in charge of the defense ministry but gave that portfolio to MBS. The king's brother, Prince Nayef, was interior minister overseeing domestic security, but his son, Prince Mohammed bin Nayef, later assumed control of the ministry.
Similarly, Prince Miteb followed in his father's footsteps. King Abdullah had been head of the National Guard, transforming it into a powerful force that protects the ruling family and key border posts, as well as Islam's holiest sites. The guard also keeps Saudi Arabia's many tribes in lockstep through an ancient system of patronage.
On Saturday, the rules were radically changed.
Prince Miteb was removed as head of the guard and allegedly detained. Months earlier, Prince Mohammed bin Nayef was ousted from the line of succession and from his post as interior minister, making way for MBS to become crown prince.
The two princes were MBS' most formidable challengers to the throne. All three are grandsons of the country's founder, King Abdulaziz, and each represented a different wing of the House of Saud.
By sidelining them, MBS consolidated power over all aspects of the kingdom's security and economy.
Also swept up in the anti-corruption purge was billionaire Prince Alwaleed bin Talal, whose father was one of three high-level royals who did not give his vote of confidence to MBS becoming crown prince and heir to the throne.
Jane Kinninmont, senior research fellow at Chatham House in Britain, says the purge will make others in the family too frightened to mobilize against MBS.
"The political system is becoming more autocratic because you are seeing more centralization of power, and you are seeing a crackdown on opposition and tightening of restrictions on free speech," she said.
For years, Saudis have complained of rampant corruption and misuse of public funds by top officials in a system where nepotism is also widespread.
The public would surely welcome efforts to eradicate both, particularly as low oil prices hurt the economy, but the arrests have simultaneously whipped up "apprehension and fear," said Madawi Al-Rasheed, who wrote several books on Saudi Arabia and is a London-based critic of its leadership.
Already, dozens of writers, intellectuals and clerics have been detained as suspected critics of MBS. Al-Rasheed said those arrested in earlier roundups were people who "simply refused to applaud every move he has started since he's become the crown prince."
While detractors of Crown Prince Mohammed see him as impulsive and erratic , his supporters call him decisive and bold.
The 32-year-old heir is betting on the support of his generation of young Saudis, who embrace the social reforms he has pushed through. Those include lifting the driving ban next year on women, curbing the powers of the religious police and easing restrictions on women's access to sports and gender segregation. He also has brought back movie screenings and concerts that were banned for 20 years.
He's spoken out about wanting to return to "moderate Islam." In remarks last month to the British newspaper The Guardian, he suggested an elder generation of royals had steered the country in the wrong direction for too long.
The prince also is betting that Saudi Arabia's ultraconservative religious establishment, which believes it has a religious duty to support the monarch, will back him even if his reforms have unnerved some. Many of these Wahhabi clerics and conservatives welcome MBS' hawkish stance toward Shiite rival Iran, as well as the ongoing security crackdown on Shiite protesters in the east, including the execution of a prominent Shiite cleric nearly two years ago.
His regional gambles, however, have not been as popular at home or abroad.
As defense minister, MBS has overseen a devastating war in Yemen that has killed 10,000 people and pushed millions to the brink of famine. On Saturday, a missile fired by Iranian-allied rebels from Yemen reached the Saudi capital, Riyadh, in the deepest strike against the kingdom since the war began in March 2015.
A spat with Qatar has pushed the tiny, energy-rich state closer to Iran and sparked the most serious diplomatic fallout in decades among Washington's Gulf allies.
The royal family appears to be split among those who support MBS and those who are quietly panicked. Several royals in government posts have stated their support for the latest purge. Other royals, wary of the unfolding events, apparently have left the country in past months.
The arrests send the chilling message that no one is untouchable or beyond the reach of the crown prince.