He has bonded with the King over bee-keeping, attended royal banquets and weddings and once flew to the rescue for an air-ambulance fundraiser led by the Prince of Wales.

Now David Beckham, who has finally been granted a knighthood, has acquiesced to another royal request: to sprinkle a little celebrity stardust on the King’s forthcoming Amazon Prime film.

The former England football captain, who is to become a knight in the King’s birthday honours, will appear in the King’s feature-length documentary, which is due to be released late this year or at the beginning of 2026.

A film crew attended St James’s Palace on Thursday for the Amazon project that is designed to “show, not tell” viewers how to “transform people, places and ultimately the planet” according to the King’s philosophy. It will focus on the work being carried out by the King’s Foundation, for which Beckham is now an ambassador.

King Charles with Penny Lancaster, David Beckham, Meryl Streep, and Kate Winslet at the King's Foundation Awards.

Lancaster, Beckham, Streep, Kate Winslet and the broadcaster Sarah Beeny turned out to support the King’s charity

CHRIS J RATCLIFFE/POOL/AP

As well as Beckham, an annual awards event at St James’s Palace was attended by other celebrity supporters, including the Oscar winners Kate Winslet and Meryl Streep, Penny Lancaster, Alan Titchmarsh, Raymond Blanc and Stanley Tucci.

Winslet, described by royal aides as “a friend of the foundation” was overheard telling the King: “Don’t worry, I’ve got your back.” Sources in the royal household suggested the British actress may reinforce her role as a supporter of the charity in the future.

King Charles speaking with Kate Winslet at an awards ceremony.

Kate Winslet was overhead telling the King not to worry because “I’ve got your back”

CHRIS J. RATCLIFFE/POOL/AP

Streep, the actress from The Devil Wears Prada, has been known to be a fan of the King for years. In a 2009 interview she said: “When I was a kid I wanted to be a princess and marry Prince Charles. When I met him I told him about it and said I was sorry it didn’t work out between us. But I’m not really sorry.”

During the charity reception, Charles, 76, stopped to talk to Lancaster, a special constable at City of London police, model and the wife of Sir Rod Stewart, who told the King that she had been keeping bees on the couple’s Scottish estate.

Speaking afterwards, Lancaster said: “We all know that the King has been at the forefront and sort of marching us all along for more than 50 years, he’s been an absolute pioneer and visionary in that sense.

“The King may have been accused of hugging trees and people thinking he was mad when he started talking about the environment all that time ago, but he was at the forefront then and now has been proved right with everything he said, and now we’re all just trying to play catch-up.”

The profile of the King’s charity has been bolstered by celebrity patronage since Michael Fawcett, a longtime aide of Charles, resigned over a cash for honours scandal. It is hoped that a feature film about Charles’s vision for a better world will secure a lasting legacy for his charitable endeavours.

Filming began in January at Dumfries House in Scotland, the headquarters of the King’s Foundation, and will focus on the philosophy outlined by the King in his 2010 book Harmony: A new way of looking at our world in which he called for a “dramatic revolution” in the way we treat the planet.

David Beckham at the King's Foundation Awards.

The King’s Foundation, previously the Prince’s Foundation, marks its 35th anniversary this year

CHRIS J RATCLIFFE/WPA POOL/GETTY IMAGES

A source close to David Beckham said that he had agreed to appear in the programme. A palace source said that the King was “greatly looking forward to seeing how the harmony concept can be communicated to a new and international audience, using some of the best creative talents in TV”.

The source added: “This is a chance to ‘show, not tell’ how they can transform people, places and ultimately the planet. I think many will be genuinely amazed at the scale, scope and vision of it all, for which Dumfries House continues to be the living laboratory”.

The Amazon film is a departure for the palace, which has previously preferred to work with UK networks such as the BBC and ITV. A film crew has spent time with the King and viewers will see him on engagements and with some of his celebrity supporters.

Meanwhile, praise of the King came from another member of the royal family. During a visit to Dartmoor to promote the importance of farming, the Prince of Wales said: “I’m keen to continue my father’s work.”

King Charles III with award recipients at the King's Foundation Awards ceremony.

The charity’s annual awards ceremony celebrates students, teachers, alumni and partners who have contributed to its work on sustainability, traditional heritage skills and environmental education

CHRIS RATCLIFFE/PA

The King’s Foundation, previously the Prince’s Foundation, marks its 35th anniversary this year. It has acquired a number of high-profile supporters, including Sienna Miller.

At the same awards ceremony last year, Sir Rod Stewart joked to Beckham about the footballer’s longstanding desire for a knighthood, saying: “I am also wonderfully honoured to be a knight and David, yours is coming soon!”

The 2025 emerging talent award was presented to Emily Hurst, who learnt the craft of straw braiding to make hats through a course with the Foundation and the French design house Chanel.

The award for young entrepreneur went to Barnaby Horn, who used to perform as a drag queen and worked in a supermarket before graduating from the Royal College of Art as an prizewinning milliner.