Many western analysts have referred to Saudi Arabia’s thirty-two-year old crown prince, Muhammad bin Salman (MBS), as the “de facto ruler” of the Saudi kingdom, acting in the name of his father, King Salman. There’s good reason for this — the state of the eighty-one-year-old Salman’s faculties has been the subject of Saudi gossip for some time now, and the kingdom’s increasingly forceful foreign policy certainly seems to bear MBS’s imprimatur alone.

But at some point, either due to his father’s eventual death or perhaps abdication (another favorite topic of Saudi speculation), MBS will become the kingdom’s de jure ruler as well. And over the past several days, under the guise of a purported anti-corruption campaign, the Saudi prince has been working overtime to sideline any potential rivals to his eventual accession to the throne.

On November 4, scores of prominent Saudi figures, including eleven princes and several of the kingdom’s wealthiest individuals, were arrested under the authority of an anti-corruption committee that had been formed — at the bidding of MBS, naturally — just hours earlier. While the Saudi media, and some particularly credulous western reporters, have dutifully characterized these detentions (and at least one royal death) as part of a crackdown on Saudi corruption, it’s difficult to avoid the conclusion that they more about removing potential sources of opposition to MBS’s succession and his policies.

The most prominent name on the list, at least to western audiences, is probably Prince Alwaleed bin Talal, chairman of the Kingdom Holding Company and one of the wealthiest people in the world (though he’s a bit poorer now than before his arrest). Bakr bin Laden — the brother of Osama and chairman of the Saudi Binladin construction giant — also stands out among the arrested.

But the most interesting targets of the anti-corruption committee, at least so far, appear to be Prince Mutaib bin Abdullah and his brother, Prince Turki bin Abdullah. Both are sons of the former King Abdullah. Turki served as governor of Riyadh for a few months in 2014-15, but Mutaib has been in charge of the kingdom’s powerful national guard since 2010 (he was fired from that post shortly before being taken into custody). Because of his position, as well as his stature within the royal family, Mutaib was a potential rival for MBS.

But to fully understand why, we need to take a brief detour into the inner workings of the House of Saud.

Since the death of Saudi Arabia’s founder, Abdulaziz Al Saud (often referred to simply as Ibn Saud), in 1953, the kingship has passed in succession to six of his forty-five sons. With that generation now well beyond its prime (Ibn Saud’s youngest surviving son, former crown prince Muqrin, is seventy-two), speculation has abounded about which of Ibn Saud’s untold number of grandsons will be next on the throne.

For some time it appeared that the honor would go to the fifty-eight-year-old Muhammad bin Nayef (MBN), the former Saudi interior minister. Now, barring any sudden changes, it is MBS who will be the first of Ibn Saud’s grandsons to rule the kingdom — and given his youth (and wealth), he may be the last.

His likely accession is significant for a couple reasons: first, it blocks many of his cousins from a path to the throne. And second, because he stands to inherit the kingdom from his father, it raises questions of nepotism in a country where power has traditionally been dispersed among the many branches of Ibn Saud’s family tree.

Mutaib bin Abdullah shared a number of characteristics with his cousin, Muhammad bin Nayef. He too was a prominent, well-regarded grandson of Ibn Saud, one of the eldest of that generation at sixty-five. Like MBN, who had built up a power base within the kingdom’s interior ministry before his ouster as minister in June, Mutaib had amassed a loyal bloc within the national guard. And now, like MBN, he’s also had his name attached to scandal after being sacked: for MBN it was rumors of drug addiction, for Mutaib it’s corruption. Replacing them — with successors no doubt hand-picked by the crown prince — has brought all three of the kingdom’s armed forces under MBS’s control (who has been serving as defense minister since 2015).

In other words, if any Saudi prince were thinking of raising an armed objection to MBS or his agenda, that prince would now certainly find himself heavily outgunned.

MBS’s signature policy is his Vision 2030 plan, which aims to shift the kingdom’s economy from one dependent on oil to one based on foreign investment. So far his plan has proven quite popular, with the crown prince focusing attention on its splashier elements and demonstrating a commitment to certain varieties of long-awaited social reform. MBS’s own popularity, particularly high among young Saudis, has also no doubt helped buoy support.

But Vision 2030 is less a forward-thinking transformation than a reaction to the decline in global oil prices and the inevitable depletion of Saudi oil reserves. It’s not going to be all IPOs and megacities in the desert and youth-friendly social changes. Eventually, painful austerity and privatization measures will be part of the reform package.

MBS has already tried to introduce austerity and been forced to ease off, but when push comes to shove and it’s time to choose between government salaries and his next war of choice (these days it’s Yemen), or between social-welfare programs and the monarchy’s financial well-being, there’s little question what a King MBS will do. Many of the business leaders who have been jailed were thought to have disagreed with parts of the Vision 2030 plan (and with parts of MBS’s foreign policy), and some — like Alwaleed bin Talal — had the money and the media prominence to become very visible opponents of the plan if they chose to do so.

A robust welfare state has always been part of the Saudi social contract: agree not to raise a fuss about the absence of democratic rights, and we’ll ensure your lives are as easy as possible. Making a show of rooting out elite corruption is a way to win popular acquiescence for shrinking government expenditures.

And there is no question that corruption is endemic to the Saudi regime — so endemic, in fact, that it’s been hard to figure out exactly what these particular princes could have done to cross the line from normal practice to something criminal. That’s part of the reason why it’s so difficult to see the purge as purely anti-corruption, especially not when MBS stands to benefit from its outcome.

MBS’s Vision 2030 initiative promises to remake Saudi Arabia’s finances, but his treatment of potential rivals has already begun to remake the Saudi state. He’s taken a monarchy in which power once rested in and across Ibn Saud’s entire family tree, where decisions were made by the king but generally with the consensus of the king’s brothers, nephews, and cousins, and turned it into a monarchy in which absolute power rests in one man: himself. In doing so, he’s fashioned himself another Ibn Saud, the founder of a new Saudi state.

But he also appears to have looked abroad for inspiration: MBS has patterned himself after no one more than his biggest American cheerleader, Donald Trump — cynically appealing to the Saudi people with a mixture of nationalism and faux populism in order to bypass the country’s other power centers and accumulate as much authority as possible.

And at least for now, it’s working. With his greatest potential rivals — and many of his critics — effectively handled, Saudi Arabia’s de facto ruler may not yet be sitting on the throne, but he is sitting pretty.