Kate Middleton's Brother Shares Support amid Cancer News with Unseen Photo: 'We've Climbed Many Mountains'

The heartfelt caption alongside the throwback photo was a warm showing of support from the Princess of Wales' younger brother

James Middleton is sharing his support for his sister after her shocking health announcement.

On Friday, Kate Middleton announced she has been diagnosed with cancer and is undergoing chemotherapy treatment. As the world reacted to the unprecedented news that a third member of the royal family currently has cancer, the Princess of Wales' younger brother shared a sweet message alongside a never-before-seen photo of the two from their childhood on Instagram.

"Over the years, we have climbed many mountains together. As a family, we will climb this one with you too ⛰️❤️," he simply captioned the photo, where the two are seen wearing backpacks in front of a mountainous backdrop.

Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!

Related: Kate Middleton Reveals She Has Cancer and Is Getting Chemo, Says It Has 'Taken Time' to Tell Her Kids

On Jan. 17, Kensington Palace announced that Princess Kate had undergone a "planned abdominal surgery" the previous day. At the time, it was understood that the issue was non-cancerous, but post-operative tests "found cancer had been present." The type of cancer has not been revealed.

A Kensington Palace spokesperson says, "We will not be sharing any further private medical information. The Princess has a right to medical privacy, as we all do."

In her emotional video, Princess Kate thanked well-wishers for their "wonderful messages of support" amid her recovery, which she called "an incredibly tough couple of months for our entire family."

"In January, I underwent major abdominal surgery in London, and at the time, it was thought that my condition was non-cancerous," she said. "The surgery was successful. However, tests after the operation found cancer had been present. My medical team therefore advised that I should undergo a course of preventative chemotherapy, and I am now in the early stages of that treatment."

The Princess of Wales concluded her video asking for privacy and the public's patience as she navigates her treatment and recovery.

"We hope that you will understand that, as a family, we now need some time, space and privacy while I complete my treatment. My work has always brought me a deep sense of joy and I look forward to being back when I am able, but for now I must focus on making a full recovery," she shared.

"At this time, I am also thinking of all those whose lives have been affected by cancer. For everyone facing this disease, in whatever form, please do not lose faith or hope. You are not alone."

For more People news, make sure to sign up for our newsletter!

Read the original article on People.