Prince Harry has paid tribute to the Prince of Wales for the care he showed to his sons in the aftermath of Diana, Princess of Wales' death, describing how he was "there for us".
Harry's words of praise come in a BBC documentary where he also appears to confirm Charles broke the terrible news to the royal brothers that their mother had been killed in a Paris car crash.
The prince was in a state of "disbelief" and said he refused to accept his mother's death while older sibling the Duke of Cambridge felt "completely numb" and asked himself the question "why me?", the programme reveals.
William and his brother have spoken candidly about their grief and Diana's death in the run up to its 20th anniversary, August 31, in a series of high profile interviews and documentaries, but until now have not spoken of their father's role.
Harry, who at the time was holidaying at Balmoral with his brother, father, the Queen and Duke of Edinburgh, said: "One of the hardest things for a parent to have to do is to tell your children that your other parent has died.
"How you deal with that I don't know but, you know, he was there for us.
"He was the one out of two left and he tried to do his best and to make sure we were protected and looked after.
"But, you know, he was going through the same grieving process as well."
The documentary Diana, 7 Days is screened on Sunday and chronicles the days after the princess' death in 1997, featuring contributions by some of the major figures at the time including former prime minister Tony Blair and other Government figures, senior royal aides, Diana's brother Earl Spencer and her friends.
The Queen faced criticism from the press and public for not returning from her Scottish estate of Balmoral to London quickly enough to acknowledge the huge outpouring of grief following the fatal car crash, that also claimed the lives of Diana's lover Dodi Fayed and the driver Henri Paul.
William said: "At the time, you know, my grandmother wanted to protect her two grandsons and my father as well.
"Our grandmother deliberately removed the newspapers and things like that, so there was nothing in the house at all, so we didn't know what was going on."
He added: "We had the privacy to mourn and kind of collect our thoughts and to try and just have that space away from everybody."
A sea of floral tributes had been left at the gates of Buckingham Palace and Diana's home Kensington Palace in the days after her death and the documentary charts the growing pressure on the monarchy to make a public appearance.
Harry attempted to explain the situation: "It was a case of how do we let the boys grieve in privacy, but at the same time when is the right time for them to put on their prince hats and carry out duties to mourn not just their mother but the Princess of Wales..."
William sympathised with the dilemma the Queen faced: "I think it was a very hard decision for my grandmother to make, she felt very torn between being the grandmother to William and Harry and her Queen role.
"And I think she, you know again like I said, everyone was surprised and taken aback by the scale of what happened and the nature of how quickly it all happened, plus the fact, you know, she was or had been challenging the Royal Family for many years before hand."
Mr Blair, who had only swept to power in a landslide victory a few months before, told the documentary he was woken on the day Diana died by a policeman at the foot of his bed and described the "shock" at learning the "most famous person in the world" was dead.
Later that day he famously described the royal as the "People's Princess" and in the documentary he attempted to sum up the historical figure.
He said: "Today now 2017, you know we see Prince William, Prince Harry as people, people feel a close connection with. They speak like normal people, they act like normal people, you know, people don't find them hard to relate to.
"It's really important to wind back 20 years and realise, I mean, she was the first member of the Royal Family that people really felt behaved and acted like a normal human being."
Mr Blair revealed in his first conversation with the Queen after Diana's death the monarch was aware of the potential harmful effect events could have on the standing of the Royal Family.
He said: "Princess Diana's relationship that she had with the monarchy and the relationship with Prince Charles, there was going to be a risk that the country's sense of loss turned to a sense of anger and grievance, and then turned against the monarchy.
"So that the first conversation with the Queen was an important conversation, she was obviously very sad about Diana, she was concerned about the monarchy herself because the Queen has a very strong instinct about public opinion and how it plays."
The documentary charts how when the Queen, with the rest of her family, decided to return to London the mood among mourners and the wider country changed.
Mr Blair said: "I think in the course of this week the monarchy, and the Queen in particular, showed that they had that capacity to adapt and adjust.
"Realising what from Diana's life they had to, as it were, keep as part of the monarchy going forward."
At the end of the programme Harry echoes comments made in another interview where he said he wanted to leave the Royal Family.
Speaking about the aftermath of his mother's death he said: "Years after I spent a long time (of) my life with my head buried in the sand, you know, thinking 'I don't want to be Prince Harry, I don't want this responsibility, I don't want this role, look what's happened to my mother, why does this have to happen to me'.
"But now all I want to do is try and fill the holes that my mother has left, that's what it's about for us, is trying to make a difference, and in making a difference making her proud."