James Middleton is "incredibly proud" of his "darling sister", Catherine, Princess of Wales following her Three Peaks Challenge.
The 44-year-old royal scaled Scotland's Ben Nevis (1,345m), England's Scafell Pike (978m), and Wales' Mount Snowdon (1,085m) solo within 24 hours last weekend, and her brother has reflected on the conversations they had when she was receiving treatment for cancer two years ago.
Sharing a photo of him and Catherine hugging, as well as one of them with their parents, Michael and Carole Middleton, the princess' husband Prince William and their three children, which were both taken after she completed the challenge, James wrote on Instagram: "I’m so incredibly proud of my darling sister .
"Two years ago, I told you we’d climb this mountain together. We talked about climbing mountains while you were in hospital, and about the incredible healing power that nature can have for both the body and the mind. So it was such an honour to join you for your Three Peaks Challenge for the Royal Marsden Cancer Charity."
James went on to praise his sister for being an inspiration to so many people.
He added: "Seeing how far you’ve come is nothing short of inspiring. Your strength, resilience, and determination, all while being the most amazing mother, wife, daughter, and sister, inspire me and so many others every single day.
"Keep being exactly who you are."
Catherine undertook the challenge to raise money for The Royal Marsden Cancer Charity, and the organisation "couldn't agree more" with James' message about the princess.
A comment on his post read: "We couldn’t agree more! We’re incredibly grateful that Her Royal Highness is Joint Patron of The Royal Marsden, and that the both of you are supporting The Royal Marsden Cancer Charity [purple heart emoji]."
After details of Catherine's challenge emerged, fellow hiker Philip Tebajjwa shared a video of the princess ascending from the top of Mount Snowdon, holding hands with her brother while his beloved dog Mabel ran behind.
He captioned the footage: "There I was, congratulating fellow climbers as they made their way down from the windy summit... little did I know I was actually speaking to royalty."
He also shared a selfie with the princess and captioned the photo in part: "At that moment, I could only think one thing...Am I actually dreaming?"
Back when Catherine's cancer diagnosis was made public in 2024, James shared a photo of them as children on a hiking trip.
He captioned the post: "Over the years, we have climbed many mountains together. As a family, we will climb this one with you too."
