Royals at 40: King Charles, Princess Anne, late Queen and more in 9 archive photos

The late Queen attended the State Opening of Parliament in all her finery the day after her 40^th birthday in April 1966. It was a momentous occasion as it marked the first time the full ceremony was televised.

Then Prince Charles celebrated his 40^th birthday publicly at Witton tram shed in Birmingham in 1988, where he was greeted with a tiered cake and a badge which read: "Life Begins at 40".

The Princess Royal celebrated her 40^th birthday with a private party at her Gatcombe Park estate in Gloucestershire, but according to reports at the time, her future second husband, Vice Admiral Laurence, was absent from the bash. Here, Anne is pictured wearing a white dress with padded shoulders as she attended a dinner at Grosvenor House Hotel.

The late Queen and Prince Philip's youngest child, Prince Edward, turned 40 in March 2004, just a few months after he and wife, Sophie, welcomed their first child, Lady Louise Windsor, in November 2003.

​​​​Sophie beamed as she was inundated with balloons and gifts as she opened a new Sixth Form Centre at Collingwood College in Camberley, Surrey.

Princess Anne's daughter, Zara, pictured at Royal Ascot, celebrated her 40^th birthday two months after welcoming her third child, Lucas, in May 2021.

To mark her 40^th birthday in August 2021, The Duchess of Sussex appeared in a video to launch a new women's work mentoring initiative. Earlier that summer, Meghan gave birth to her second child, Princess Lilibet.

Kate, pictured at Wimbledon, was captured by renowned photographer Paolo Roversi, for three stunning official portraits to mark her 40^th birthday in January 2022.

Prince William, pictured in Cambridgeshire after his 40^th birthday, volunteered with the Big Issue for his milestone in June 2022.