Who is royal cousin Arthur Chatto, the heartthrob environmentalist and serving Marine who turns 25 today?

It seems like a world ago on February 5, 1999 Princess Margaretha's grandson made his first royal appearance in front of the public as a page of honor for the late queen.

He held the role between 2009 and 2015 was responsible for wearing his great aunt's dress during ceremonial events.

Now turning 25, action man Arthur Chatto makes a living as a member of the Royal Marines, the first Royal Marine to join the regiment. He is the 30th in line to the throne.

After attending Westminster Cathedral Choir school, Arthur followed in the footsteps of Princes Harry and William by attending Eton College.

He is the youngest son of Princess Margaret's daughter, Lady Sarah, and Daniel Chatto

Arthur made royal history in 2021 when he became the first member of the Royal Family to join the Marines

At Eton he was part of the Combined Cadet Force, which teaches students a range of military skills. He then followed his older brother Sam to the University of Edinburgh.

Arthur, who studied art history, combined his studies with a job as a personal trainer at the BoundFitness gym in the city.

In a profile of the young royal, shared on Instagram, Arthur wrote: 'I am a level 3 personal trainer, I specialize in strength and endurance training with a military focus.'

Princess Margaret's grandson is also said to be a fan of outdoor sports, including mountain climbing. The adventurous monarch has even done ice diving in Greenland and climbing in the Alps.

Arthur, who like Prince William and Harry is a keen environmentalist, was also part of a four-man team that completed an epic romp across Britain to raise money for the British Red Cross and Just One Ocean in 2020.

Speaking about the 3,800km GB Row Challenge, which took 38 days to complete, Arthur said preparing for the challenge had been 'mentally' and physically very demanding.

The preparation was not easy, as he reportedly went on 20-mile walks and camped in the Scottish Highlands in preparation for his uniformed role.

Arthur, left, was part of a four-man team that completed an epic feud around Britain in 2020

Arthur Chatto in uniform with brother Samuel. Standing in front of them are father Daniel and their mother Lady Sarah Chatto during Queen Elizabeth II's state funeral in Westminster Abbey.

Princess Margaret's grandson Arthur is also said to be a fan of outdoor sports, including polar diving and mountain climbing

The Chatto family attends the Cartier Style & Luxury Lunch at the Goodwood Festival of Speed ​​in 2012. Arthur stands next to his mother

Arthur was greeted at the finish line at St Katherine Docks in London by his family and his long-term girlfriend, Lizzie Friend.

Lizzie was a fellow student at the University of Edinburgh, where Arthur studied, and a source previously told the Daily Mail: 'We hit it off straight away.

'She is very sweet and they make a very nice couple. He took her to Royal Ascot this summer as his date.'

Arthur has also made royal history, as in 2021 he became the first member to join the Marines. The late queen is said to be 'pleased and proud' of her great-nephew's achievements.

He has since turned heads as a royal heartthrob when he wore his Marine uniform to the Queen's Thanksgiving service at St Paul's Cathedral in 2022.

Arthur amassed a following on his now-deleted Instagram account after often posting revealing snaps, including a topless photo taken during a 'Scottish dip' with older brother Samuel during his freshers' week at university.

Arthur made his first royal appearance to the public as Page of Honor for the late Queen, a key role he held between 2009 and 2015

Arthur followed in the footsteps of Prince Harry and Prince William by attending the £33,270-a-year Eton College before heading to the University of Edinburgh

Although there is no official Instagram account, this has not stopped Arthur's photos from surfacing as adoring fans have kept his online presence alive by creating fan pages where they share photos and videos of the royal family.

The royal family seems to have enjoyed watching The Crown, he admitted to The Telegraph.

Arthur said, “Yes, I looked at it, I think it's just an interpretation. So I just kind of remember what they really are like and don't let the TV personality taint my judgment of any of them.”