What Prince William said in rare comment about brother Harry after sharing never-before-seen photo of them with Princess Diana

Prince William has spoken about his brother, Prince Harry, in a new ITV documentary.

It's not often that William speaks publicly about his younger sibling, especially since Harry and wife, Meghan Markle, stepped down from their roles as senior royals and moved to America.

Then, there were the multiple explosive interviews that followed, and Harry's tell-all memoir Spare, which led to further tensions within the royal family.

But in a new documentary, titled Prince William: We Can End Homelessness, William opens up on a touching moment in his and Harry's childhood.

In the doc, viewers see William co-found a new initiative called Homewards, which aims to overhaul the scale of homelessness in the UK.

Speaking about visiting The Passage - which is London's largest homelessness charity - William recalls: "My mother took me to The Passage; she took Harry and I both there.

"I must have been 11 at the time, maybe 10.

“I had never been to anything like that before, and I was a bit anxious about what to expect.

“My mother went about her usual part of making everyone feel relaxed, and having a laugh and joking with everyone.

"I remember at the time, kind of thinking, well, if everyone’s not got a home, they’re all going to be really sad.

“But it was incredible how happy an environment it was."

The Passage also took to Instagram to post about the doc and shared a series of photographs of Princess Diana and the boys.

"‘Prince William: We Can End Homelessness’ will give an exclusive, behind the scenes look at the first year of this five-year programme; whilst presenting our shared mission to change perceptions and demonstrate that it is possible to end homelessness," they wrote.

The Passage Chief Executive, Mick Clarke added: “For William this is personal. He has a long history of involvement on this issue, back to when his mother took him to The Passage when he was 11... That is where the genesis of @HomewardsUK came from."

In the photos, William and Harry can be seen at The Passage with Diana, meeting, chatting and playing games with the residents.

“I remember having some good conversations - just playing chess and chatting," William added.

"That’s when it dawned on me that there are other people out there who don’t have the same life as you do."

William also spoke about some of the criticism he had received about tackling homelessness, given his privileged position.

Asked how he feels about criticism of Homewards, he said: "I think if I answered every critic, I’d be here all day. But you know, criticism drives you forward.

"I think it’s right to question but I think, ultimately, we are pushing forward to deliver change and hope and optimism into a world that frankly has had very little of it for a long time.

"I hope I can bring something that’s not been done before.”

Prince William: We Can End Homelessness will air on ITV on October 30th and 31st.