He has travelled the world in the line of royal duty, taking in the planet's most spectacular scenery in a lifetime of overseas tours, charity trips and private holidays.
All the while, the Duke of Sussex has been recording the sights on camera, he has disclosed, as he shares a series of photographs from his previously-unknown hobby.
The Duke, who is expected to increase his focus on conservation work in the coming years, has released eight pictures on Instagram as he and the Duchess urge the public to "learn about, celebrate and continue to safeguard our planet, our home".
In a 351-word caption marking #earthday, the Duke and Duchess told their 4.9m social media fans: "Every one of us can make a difference, not just today but everyday."
Fans have noted that the Sussexes are increasingly embracing their ability to control the release of "unseen" pictures on Instagram to highlight their work, writing in-depth captions about charities and detailing previous endeavours behind-the-scenes.
Their most recent Instagram post - the 14th since they launched @SussexRoyal on April 2nd - told followers: "We invite you to scroll through a series of 9 photos taken by The Duke of Sussex sharing his environmental POV [point of view]."
The Duke has hitherto kept his photography hobby largely under wraps. During an autumn tour of Australia, Tonga, Fiji and New Zealand, he allowed the Kensington Palace social media account to share a handful of personal photographs and videos taken during the course of the trip.
He has now issued a series of eight images taken as he has flown around the world to Botswana, Guyana, Norway, Malawi and beyond, shot in private moments during his tours, charity trips or leisure time.
The message, which was posted at 3pm BST and 10am for their American audience, outlined the eight different scenes chosen by the Duke beginning with the animal they called the "African Unicorn" - better known as the rhino.
"These magnificent animals have survived ice ages and giant crocodiles, amongst other things!" the couple said.
"They have adapted to earth's changing climate continually for over 30 million years. Yet here we are in 2019 where their biggest threat is us."
Other pictures included the forest of Guyana, where Prince Harry went on tour in 2017, the orca and humpback whales of Norway, and an elephant in Malawi with a helicopter flying in the background.
One image showed plastics pollution on a pebble beach, another showed a close-up on a desert lion's eyeball, and a particularly artistic shot captured two feathers in front of a sunset in Botswana's Okavango Delta where "huge bush fires, predominantly started by humans, are altering the entire river system".
Members of the modern Royal Family have long taken their own record of trips, from the watercolour sketches commissioned by Queen Victoria and Albert to the official artist the Prince of Wales likes to take on tour.
The Queen has often been seen with a camera capturing personal memories, and the Duchess of Cambridge has shared some of her efforts with the world in the select birthday pictures of her children.
More unusually, the Duke and Duchess of Sussex are now choosing to delight fans with greater regular insight into their personal lives, using Instagram to share their own pictures and carefully handpicked information.
Earlier this month, they used the medium to reveal that the then-Meghan Markle undertook elephant conservation work with Prince Harry when they were dating in 2017.