The King also attended an anniversary performance at the National Youth Music Theatre with Idris Elba

Britain's King Charles III greets Helen Mirren during a Royal Garden Party at Buckingham Palace, in London

King Charles III greets Helen Mirren during a Royal Garden Party at Buckingham Palace on May 14, 2026.Credit : Aaron Chown / POOL / AFP via Getty

King Charles continued celebrating the 50th anniversary of his King’s Trust charity this week, with some special celebrity guests.

The King, 78, hosted a garden party at Buckingham Palace on Thursday, May 14, 2026, welcoming dignitaries, beneficiaries, volunteers, staff and supporters who have helped him evolve the organization throughout the years, with a mission towards helping disadvantaged young people in the U.K. and “supporting them to build the confidence and skills to live, learn and earn.”

Included on the guest list for the garden party was acclaimed actress Helen Mirren, who was made a Dame Commander of the Order of the British Empire (DBE) in 2003 by the King’s late mother, Queen Elizabeth.

Over the course of her storied career, Mirren, 80, has played multiple members of the British royal family. But she received some of her greatest acclaim for playing the late Queen Elizabeth — not once, but twice. After winning the Academy Award for the 2006 film The Queen, which centers on the royal family’s reaction to Princess Diana’s death, Mirren took her portrayal to the stage, winning both a Tony and an Olivier for The Audience, which depicted the weekly meetings between the monarch and the revolving cast of U.K. prime ministers during her time on the throne.

Queen Elizabeth II meets with Dame Helen Mirren (R) at a performing Arts reception at Buckingham Palace on May 9, 2011 in London, England.

Queen Elizabeth meets with Dame Helen Mirren at Buckingham Palace on May 9, 2011.Dominic Lipinski – WPA Pool/Getty

Mirren met Queen Elizabeth a handful of times before she died in 2022, but the actress has said that the notoriously private monarch never commented on her portrayals.

“She has always been incredibly gracious, but she never mentions my playing her,” Mirren told Playbill in 2015. “I think that’s absolutely appropriate.

“The royal family — and the Queen, in particular — have always been very liberal because we come from a country that has free speech,” she added. “There have been films mocking them and suggesting they were Nazis and abusing them in all kinds of different ways, and, through it all, they have never said a word. They just let that happen. They don’t defend themselves. They don’t say anything. In a sense, it’s not their role to critique that particular world.”

King Charles III greets Helen Mirren and Damian Lewis during a Royal Garden Party at Buckingham Palace

King Charles greets Helen Mirren and Damiam Lewis during a Royal Garden Party at Buckingham Palace on May 14, 2026.Aaron Chown / POOL / AFP via Getty

Earlier in the day, the King joined another U.K. acting legend, Idris Elba, to attend events in celebration of the 50th anniversary of the National Youth Music Theatre (NYMT). Not just a supporter of the creative space, Elba is also an alum, having used a grant from what was then The Prince’s Trust to attend NYMT when he was just 18.

Together, the King and Elba met with young students taking NYMT workshops like improvisation, designed to develop their confidence and performing skills. They also watched a performance from current students, met with alumni and snapped a group picture with the talented teens.

Britain's King Charles III and English actor Idris Elba pose with students who are taking part in workshops

Idris Elba and King Charles pose with students who are taking part in workshops organised by National Youth Music Theatre (NYMT) at The Other Palace on May 14, 2026.Kin Cheung – WPA Pool/Getty

Later, Elba was also a guest at the palace garden party.

A clip posted to social media by royals reporter Rebecca English showed the hilarious moment that the actor — who is also a DJ — and Christian St. Louis put the King’s skills on the turntable to the test. When King Charles pressed one button, getting the soundboard to emit a beat, Elba turned to reporters with an impressed look, earning laughter from the crowd.

King Charles III with Christian St Louis and Idris Elba during a Royal Garden Party at Buckingham Palace on May 14, 2026 in London, England.

King Charles, Christian St. Louis and Idris Elba oversee the DJ booth during a Royal Garden Party at Buckingham Palace on May 14, 2026.Aaron Chown – WPA Pool/Getty

King Charles reflected on his charity’s 50-year milestone during a star-studded reception in New York City last month.

“It’s a wonderfully proud but extraordinary moment to think that it’s 50 years since I started this trust,” he said. “Perhaps you can imagine that after all these years of investing in young people… the greatest thing that I always hoped, but never quite believed would happen, having invested, many of the people who’ve been successful through the trust then come back to help support other young people in the future.”

“That for me has been a wonderful virtuous circle,” the King said. “I won’t see the long-distance future, but I’m enormously grateful to you all for what you can all do as supporters to help this vital endeavor, to champion the next generation, ensuring that their talent and ambition continue to strengthen our societies for many years to come.”