Prince William Admits Who Made Fateful Decision For Harry and Himself To Walk Behind Diana's Coffin 

Prince William  and Prince Harry  have been made to march behind the coffin of their mother Princess Diana?

At the time, Diana’s brother, Charles, 9th Earl Spencer, argued against them being part of the procession — and some government advisers were wary too. But friends of the royal family have said that it was their grandfather, Prince Philip, who told the princes — then ages 15 and 12 — “If I do it, will you?”

, “It wasn’t an easy decision, and it was a collective family decision to do that. It was one of the hardest things I’ve ever done. But we were overwhelmed by how many people turned out, it was just incredible. There was that balance between duty and family and that’s what we had to do.”

Harry recalls, “I think it was a group decision. But before I knew it, I found myself with a suit on with a black tie and a white shirt, I think, and I was part of it. Genuinely, I don’t have an opinion on whether that was right or wrong. I am glad I was part of it. Looking back on it now, I am very glad I was part of it.”

William calls the march a very “long and lonely walk.” He says he hid behind the floppy blond bangs he had as a teen, calling them “my safety blanket,” while noting,”the balance of me being Prince William and having to do my bit versus the private William who just wanted to go into a room and cry because he’d lost his mother.”

Harry says he remembers hearing people screaming in the crowds. “The broadcast news today still talks about the silence and of course there was a huge amount of silence, but what I remember is every 50 yards or whatever certain people in the crowd just unable to contain their emotion. That was a big thing.”

Calling it an “alien environment,” William says, “I couldn’t understand why everyone wanted to cry as loud as they did and show such emotion as they did, when they didn’t really know our mother. I did feel a bit protective at times — I thought you didn’t even know her, why and how are you so upset?

“Now, looking back, I’ve learned to understand what it was that she gave the world, what she gave a lot of people. Back in the ’90s there weren’t a lot of public figures doing what she did, so she was this ray of light in a fairly gray world.”

William added, “Both our parents brought us up to understand that there is this element of duty, and responsibility that you have to do things you don’t want to do. When it becomes that personal, walking behind your mother’s funeral cortege, it goes to another level of duty. But I just kept thinking about what she would want and that she’d be proud of Harry and I and effectively she was there with us. It felt like she was walking alongside us to get us through it.”

As discussions raged through the week, Prime Minister Tony Blair’s office worked alongside Buckingham Palace courtiers to plan and prepare for the funeral.

The princes’ uncle, Charles, 9th Earl Spencer, called the walk a “tunnel of grief” and told PEOPLE and

on NBC he didn’t believe that “tiny” Harry should have made the grueling walk.

“I was just so worried — what a trauma for a little chap to walk behind his mum’s body,” Spencer said. “It’s just awful. And, actually, I tried to stop that happening, to be honest.”

WATCH: Prince William Finally Reveals Who Decided He and Harry Should Walk Behind Diana’s Coffin

Blair’s aide Anji Hunter recalls in the BBC documentary that she made “an intervention on that — I thought, ‘How can he, [at] 12 walk, behind his mother’s coffin?\'” But Hunter says she found it “astonishing and so moving” to see the boys undertake the task.

Meanwhile, Blair’s spokesman Alastair Campbell tells the documentary, “There was doubt until the final day as to whether the boys would feel able to do it, up to do it, whether they should do it.”

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