"He didn't flinch when the request came in."

These are the words of a royal source when asked whether Prince William had shown any resistance to the UK government's request that he visit Saudi Arabia.

"He takes his role as Prince of Wales very seriously, so when the government asks, he goes," the source told me.

But this trip - the prince's first to Saudi - is something of a diplomatic maze.

Previous official visits to Estonia, Poland, Brazil and South Africa have not been as sensitive - Saudi Arabia is a whole different ballgame.

Arriving on Monday, the trip will focus on energy transition and young people - key areas of development in a country undergoing significant change.

Prince William is visiting Saudi Arabia that looks very different from the one his grandmother visited during her 70-year reign. The regime remains authoritarian and is led by an absolute monarchy, but culturally, society has been opening up, and the country is seeking to diversify its economy beyond oil.

The list of high-profile entertainment and sporting events on Saudi soil is expanding, like the Riyadh Comedy Festival, which last year featured an all-star - and predominantly male - line-up of heavyweights including Dave Chappelle, Kevin Hart and Bill Burr.

Also on the calendar is the Red Sea International Film Festival in Jeddah, the Saudi Formula One Grand Prix and, in 2034, it will host the men's football World Cup - one of the highest profile events in sport.

Human rights groups, including Amnesty International, have accused Saudi leaders of using sport and comedy to whitewash its human rights record. The kingdom's Crown Prince Mohammed bin Salman has previously said he "doesn't care" how it is labelled, as long as it is good for the Saudi economy.

Meeting Mohammed bin Salman will be an important element of Prince William's visit. Known by his initials, MBS, the crown prince is Saudi Arabia's de facto leader and a controversial figure.

William will be thoroughly briefed before this trip.

He will know about Saudi Arabia's human rights record, where same-sex relationships are criminalised, and public protest and political dissent are punished. William will also be aware of women's roles and treatment in the country. While it has given women more freedom in recent years (in 2018, they were allowed to drive for the first time in decades), there are still enormous limitations compared with men.

Importantly, William will also have been briefed on MBS's reputation and history.

Will he bring up these topics in his discussions with the crown prince?

Kensington Palace will not comment on plans for private conversations, but given the diplomatic sensitivities, it is hard to imagine William not touching on some difficult subjects during their private audience.

He will be guided by the Foreign Office in London and the British Embassy in Saudi Arabia, which will help him navigate any discussions with an eye on positive outcomes for the UK.

The visit comes after a challenging seven days for the Royal Family, as the Epstein files continue to bring further embarrassment.

The latest release has heaped further damage on the British royals and sped up the move of Andrew Mountbatten-Windsor from his Royal Lodge mansion, where he lived for more than 20 years, to the Sandringham Estate.

It is far from the ideal backdrop for a major international trip, but sources say Saudi Arabia is the top priority for the UK government, which wants to strengthen ties with MBS.

To do so, it is using a member of the Royal Family whom it feels can make an impact.

"He is a diplomatic secret weapon – a formidable tool for the government to deploy," a source explained.

Prince William, who has discussed his vision for a modern monarchy, is visiting a country in transition.

"Saudi Arabia has been opening up massively over the past decade," said Dr Neil Quilliam from the Middle East and North Africa programme at Chatham House, the international think tank.

"This younger generation of policy makers is much more transactional than their forefathers; there is greater competition for Saudi investment in the UK," he explained.

"The Saudis really like and appreciate being recognised, and deploying Prince William sends a signal that says we really value you."

But the images we'll see this week of William with MBS will be difficult for many to stomach.

A 2021 US intelligence report found that the Saudi crown prince approved the murder of exiled Saudi journalist Jamal Khashoggi in 2018.

The report, released by the Biden administration, said MBS approved a plan to either "capture or kill" Khashoggi.

Saudi Arabia rejected the report, calling it "negative, false and unacceptable" and MBS has denied any role in the murder.

Amid the moves to modernisation, what hasn't changed is the Saudi authorities' attitude to its critics - both within the kingdom and abroad.

In January, a judge in a UK court ruled that Saudi Arabia should pay Ghanem al-Masarir damages of more than £3m.

The London based YouTuber and satirist had used his online voice to attack the Saudi regime. He told the court that he'd been followed, assaulted and had his phone bugged by agents acting for the kingdom, and that as a result he suffered psychological damage.

The judges agreed with him.

Despite his experience, al-Masarir is not against Prince William's visit, but urges the UK's future king not to hold back.

"I understand why he is going - to strengthen Saudi-UK relations. I have no problem with him going… Prince William has a privileged place and opportunity to speak to Mohammed bin Salman," al- Masarir said.

"But to see them up there shaking hands - it is not real," he continues. "Prince William will be standing next to a guy, who we know the CIA has said ordered the killing of Khoshaggi… it's something you cannot comprehend".

The murder of Jamal Khashoggi and public opinion of Saudi Arabia's human rights record does not appear to have limited the courting of MBS by world leaders - William joins an illustrious list of visitors.

A look back at recent guests says a lot about Saudi Arabia's influence: US President Donald Trump, France's Emmanuel Macron, Chancellor Friedrich Merz of Germany, Ukraine's Volodymyr Zelensky, and the UK's Prime Minister Sir Keir Starmer.

Even Joe Biden, who once pledged to make Saudi Arabia a "pariah" over its human rights violations, then travelled to Jeddah, amid a storm of criticism, to meet the crown prince in 2022.

It is the dilemma of being in the room even when some aspects of that country's leadership don't align with your beliefs.

This is what the British Royal Family has traditionally excelled at: the view that if you build relationships and strong ties, you open the door for the government to more easily address problematic and sensitive subjects. That is the soft power of monarchy.

This trip also brings together two royal families.

William's father, King Charles, has visited Saudi Arabia often, both publicly and privately, and maintains a warm relationship with the current generation of Saudi royals.

"King Charles loves the desert, and he spends a lot of time there in Saudi Arabia, painting and looking at the wildlife and likes the beauty," a former British senior diplomat to Saudi Arabia told me.

"There is a special link between the two royal families… There is affection between the two Kingdoms and a lot of shared history."

This will be another stage in what those who work with Prince William call his development as a global statesman.

His job will be to facilitate and solidify relationships in a region of great strategic importance to the UK.