Following a video that was released yesterday to reveal Kate’s conclusion of preventative chemotherapy treatment, James Middleton has been quick to react.

Taking to the comments section below the emotional clip posted on social media, the Princess’ brother shared: “I couldn’t be more proud.”

James Middleton, 37, is a British entrepreneur and the youngest child of Carole and Michael Middleton.

The footage saw Kate and her husband Prince William both 42 celebrating the news of her recovery with their family.

Prince George, 11, Princess Charlotte, nine, and Prince Louis, six, all took part in the filming.

Kate and James’ parents were also captured in the heart warming clip, playing cards with Kate’s family at Anmer Hall, their Norfolk home.

Earlier this year, Kate was spotted at Wimbledon with her sister Pippa Middleton, 41, showing her support.

When the Princess first revealed her diagnosis in March, James shared a childhood picture of the pair on a hiking trip.

He wrote: “Over the years, we have climbed many mountains together. As a family, we will climb this one with you too.”

The siblings have supported each other over the years, with James previously admitting that both Kate and Pippa attended therapy sessions whilst he struggled with clinical depression.

James added: “I was very lucky that they were willing to be involved and understood that it’s a process, there’s no quick fix to it.

“And understanding the way that my mind works, which may differ from theirs or other people’s is a really important part, because it was was a process for me as much as it was a process for them, and I think as a family we grew from that.

“My sisters came to some of my therapy session. They’ve always been there during difficult times and they were at my side during the hardest of times as well. For that, I am forever grateful.”

The video released yesterday was filmed in Norfolk with the Princess speaking over the footage.

Kate said: “The last nine months have been incredibly tough for us as a family. Life as you know it can change in an instant and we have had to find a way to navigate the stormy waters and road unknown.

“The cancer journey is complex, scary and unpredictable for everyone, especially those closest to you.

“With humility, it also brings you face to face with your own vulnerabilities in a way you have never considered before and with that, a new perspective on everything.

“This time has above all reminded William and me to reflect and be grateful for the simple yet important things in life, which so many of us often take for granted. Of simply loving and being loved.

“Doing what I can to stay cancer free is now my focus. Although I have finished chemotherapy, my path to healing and full recovery is long and I must continue to take each day as it comes.

“William and I are so grateful for the support we have received and have drawn great strength from all those who are helping us at this time. Everyone’s kindness, empathy and compassion has been truly humbling.

“To all those who are continuing their own cancer journey – I remain with you, side by side, hand in hand. Out of darkness, can come light, so let that light shine bright.”