Some see the arrests as an attempt by Saudi Crown Prince Mohammed bin Salman to consolidate power

In a ballroom in a hotel in Riyadh, being held against their will are some of the richest men on Earth.

It is hard to think of a gilded cage that's ever held people worth more than those currently under hotel arrest in the Saudi capital. Individually, some of them are worth as much as $20bn (£15bn).

Eleven Saudi princes and two score officials detained in an unprecedented round-up. And if we are to believe the pictures released by the Saudi government, sleeping on thin mattresses on the ballroom floor.

It is being seen as a palace purge - a real-life Game Of Thrones manoeuvre by an impatient young heir securing his path to the throne.

But it is potentially much more than that. It is a bold declaration of intent by a ruler-in-waiting about the revolution he plans for his country.


Image: All those detained under the crackdown are being held at a five-star hotel in Riyadh

Mohammad bin Salman is only 32 years old. He has had an extraordinary rise to power since his father's ascent to the Saudi throne and has displayed breathtaking ambition on the way up.

Not satisfied with being made Crown Prince and heir to the throne, he is determined to cement his grip on power as his father becomes increasingly frail and to guarantee his succession when he dies.

He appears to be unstoppable. Donald Trump has given him his unqualified support. And unusually for an Arab leader, he is currently genuinely popular among ordinary Saudis because they hope he will usher in a long-awaited period of modernisation and change.

"He is the first prince whose real power base is outside the family and comes from ordinary people," Sir John Jenkins, former UK ambassador to Saudi Arabia told Sky News.

He knows that of 21 million Saudis, 12 million are under 30. His success as ruler, whenever that begins, will depend on how he addresses their needs. He knows fundamental economic reform is required to do that.

Image: Mohammad bin Salman is thought to have led Saudi efforts to court President Trump

Until now the Saudi economy has been built on patronage networks - family based conglomerates in oil, energy, construction and infrastructure that have concentrated wealth and power in the hands of the few. Ordinary Saudis resent their wealth and accuse them of wholesale corruption.

MBS, as he is known for short, has signalled he wants that model upended. He wants it replaced it seems with a new model based on private sector enterprise, entrepreneurialism and greater economic and social freedom.

The princes currently under hotel arrest pending corruption investigations run some of the biggest of Saudi conglomerates.

Their arrests certainly could be designed to purge the Saudi court of an old guard that could threaten the young heir's passage to the throne.

But they also represent the old ways of doing business in the kingdom. Judging from the reaction to their arrests on Arabic social media channels, there is a clamour to see them prosecuted. This is unlikely to be a token effort.

Saudi Arabia detains 11 princes and dozens of ministers in 'corruption crackdown'

So where does leave their enormous wealth? What does it mean for billions of dollars worth of investments held by the arrested princes around the world and their business interests at home?

"My guess is he will also want to break up their commercial empires," said Sir John.

This unprecedented move has raised expectations among ordinary Saudis that their popular king-in-waiting is serious about his promise to reform and modernise their country.

He will have to follow through now to avoid too much disappointment. Rounding up princes in a five-star hotel will be just the beginning.