The Prince of Wales has said he will bring change to the monarchy when he is king, in an interview palace sources say is the most open Prince William has ever been.

The Prince was speaking to the actor Eugene Levy in Windsor, for the Apple TV+ show The Reluctant Traveller.

In a revealing conversation, the actor asked Prince William about his future role as King.

"I think it's safe to say that change is on my agenda," he said.

"Change for good, and I embrace that, I enjoy that change. I don't fear it; that's the bit that excites me, the idea of being able to bring some change. Not overly radical, but changes that I think need to happen."

The prince made the comments as he gave Levy a tour of Windsor Castle.

William arrived to meet the actor on an electric scooter that he said he used to get around the castle grounds.

He said he had been a fan of the American Pie series of films – the bawdy coming-of-age movies in which Levy played a long-suffering father.

During the tour of some of the castle's grandest rooms, Prince William also spoke about his family history.

"I think if you're not careful, history can be a real weight and an anchor around you, and you can feel suffocated by it and restricted by it too much.

And I think it's important to live for the here and now."

Prince William stresses the importance of tradition but says he isn't afraid to ask questions to keep the monarchy relevant.

"There are points when you look at tradition and go, is that still fit for purpose today? Is that still the right thing to do? Are we still doing and having the most impact we could be having?

"So I like to question things, is what I'm really getting at."

The conversation takes the Prince and the actor on a dog walk around the Castle with the family dog, Orla.

They talk about family, children, media intrusion and being an Aston Villa fan.

And the strain of coping with both his father and his wife dealing with cancer is a recurring theme of their exchanges.

"Stuff to do with family overwhelms me quite a bit. You know, worry or stress around the family side of things - that does overwhelm me quite a bit."

The Prince takes the actor to the Two Brewers pub close to Windsor Castle.

Levy orders a pint of Guinness, and Prince William has a pint of sweet cider.

It's an informal setting where the Prince seems relaxed, especially when talking about his family and how his children coped when their mother was unwell.

"We try to make sure we give them the security and the safety that they need," he told Levy.

"And we're a very open family, so we talk about things that bother us, and things that trouble us, but you never quite know the knock-on effects that it can have.

"And so, it's just important to be there for each other and to kind of reassure the children that everything is okay."

The interview does not touch on the state of relations with Prince Harry.

But Prince William does mention his brother when asked about his experience of royalty growing up with the intense scrutiny his mother and father faced.

"I hope we don't go back to some of the practices in the past that Harry and I grew up in. And I'll do everything I can to make sure we don't regress in that situation."

Speaking to the BBC, Levy said he was surprised at how candid the Prince was during the interview.

"To me, it was just a conversation. I wasn't thinking about it in my own mind as any kind of scoop," he said.

"He was telling me what his thoughts were and we were able to have a little back and forth. It was a totally surreal day for me."

And as the prince and the actor finish their pints and round off their day together, the prince says he wants to create a world his son would be proud of.

"You know life is sent to test us as well and it definitely can be challenging at times, and being able to overcome that is what makes us who we are.

"I'm so proud of my wife and my father, for how they've handled all of last year. My children have managed brilliantly as well."