Nearly 20 years after Princess Diana‘s tragic death, a new documentary about the late People’s Princess is coming to the small screen.

Scroll down to see everything we know so far about the feature — titled Diana, Our Mother: Her Life And Legacy — on Prince William and Prince Harry’s mom.

When will it air?

Diana, Our Mother: Her Life And Legacy is set to air on ITV in the UK later this month. It will also be available via HBO in the US.

MORE: Prince Charles “Made a Huge Mistake” Marrying Princess Diana

What will the documentary include?

According to ITV’s Jo Clinton-Davis, the new film “will offer viewers a fresh and revealing insight into Princess Diana through the personal and intimate reflections of her two sons and of her friends and family, many of whom have never spoken before, to bring together a definitive portrait of a unique person who touched the lives of millions.”

While other recent documentaries have chosen to delve into the late Princess’s private life, Diana, Our Mother: Her Life and Legacy is shaped around contributions from William and Harry, who will pay tribute to the ways in which Diana’s influence has shaped their own lives, and the charitable causes which they have chosen to champion.

MORE: Prince William on His Mother Princess Diana’s Death — “It Makes Me Sad She Never Met Kate, George, and Charlotte”

Will the royal family be in it?

Yes! Both of Diana’s sons, William and Harry, will appear in the highly-anticipated documentary. In the newly-released trailer for the upcoming film, the royal brothers can be seen leafing through a family photo album, and recalling some of the happiest moments from their childhood.

princess diana getty images

Diana, Harry, and William in 1993. (Photo Credit: Getty Images)

“This is the first time that the two of us have ever spoken about her as a mother. She was our mum. She still is our mum,” Harry said in the short promo. “And of course, as a son I would say this, she was the best mum in the world. She smothered us with love, that’s for sure.”

“She was very informal and really enjoyed the laughter and the fun. She understood that there was a real life outside of Palace walls,” William added.

Part of this story originally appeared on Grazia Daily.

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