The Prince and Princess of Wales have marked their youngest son’s birthday with a rare glimpse of his fun-loving nature.

Prince Louis turned eight on April 23 and, to mark the occasion, his parents released a photo and a video montage on Instagram.

The footage shows the young prince at a beach in Cornwall, enjoying a range of outdoor activities. He is seen digging in the sand with a toy spade, hitting a ball with a cricket bat and running across the foreshore.

There are also scenes of the adventurous child wearing a full wetsuit and jumping into the water from a height.

The video was reportedly filmed by photographer Matt Porteous earlier this month on the family’s holiday.

“Thank you for all the birthday wishes for Prince Louis. 8 is great!,” wrote the Prince and Princess of Wales alongside the footage.

Louis is fourth in line to throne, behind his father Prince William and older siblings Prince George and Princess Charlotte.

Kate and William also released a new photo on X, which was taken on the same family break. The picture, taken by Porteous, shows a grinning Louis on a boat with the sea behind him.

“Happy birthday, Louis! 8 today!” William and Kate posted on X.

Earlier in the week, the Princess of Wales marked Earth Day with a rare personal statement.

She posted five landscape images from her Mother Nature video series, signing off with a C to indicate it came from Catherine herself.

“When we listen to the rhythms of Mother Nature, we remember where we belong,” she wrote.

Kate’s message came a day after she and Prince William joined the King and Queen to mark what would have been the 100th birthday of the late Queen Elizabeth II at a reception at Buckingham Palace on Tuesday.

Guests included some of Britain’s oldest citizens celebrating their 100th birthday on April 21. The King presented them with centenary cards.

Kate and William mingled and chatted with guests, and the princess shared a poignant moment with former Met Police officer Tony Gledhill. He shared a hug with Kate after telling her his wife of 67 years had recently died.

“The princess was lovely, she was fantastic,” Gledhill said afterwards.

Video of the pair’s touching encounter was shared by multiple outlets, including Woman’s Day.

The King paid a tender tribute to his late mother in a video message released this week, saying his “darling mama” will “remain forever ‌in our hearts and prayers”.

“Millions will remember her for moments of national significance. Many others ​for a fleeting personal encounter, a smile, a kind word that lifted spirits, or for that marvellous twinkle of the eye when sharing a marmalade sandwich with Paddington Bear in the final months of her life,” he said in the message recorded at Balmoral Castle.

-with AAP