It's a memory that has stuck with the public since that September day in 1997, but there are two people in particular who are especially haunted by it.
A few days before the Princess of Wales' funeral in London, Prince Harry and his older brother, William, were asked to walk behind the gun carriage carrying Diana. Naturally, both boys were reluctant to do something so public while still dealing with their loss, but both their father and Diana's younger brother, Charles Spencer, gently urged them to reconsider.
Finally, Prince Philip reportedly asked William, "If I walk, will you walk with me?'
It was painful to watch. The expressions on the boys' faces was one of anger mixed with sadness that even today makes one choke up.
Twenty years later, Harry made his feelings known about the whole ordeal.
“My mother had just died, and I had to walk a long way behind her coffin, surrounded by thousands of people watching me while millions more did on television,” the prince told Newsweek in an exclusive interview. “I don’t think any child should be asked to do that, under any circumstances. I don’t think it would happen today.”
Harry and William have only recently opened up about how they've coped with Diana's death over the years. The princes took part in a BBC documentary that airs later this summer, the only one they've agreed to be part of as several networks prepare to air programs marking the anniversary.
The prince granted Newsweek access into his personal life, which was documented for the better part of a year. He admitted to the writer of the piece, Angela Levin, that it's taken him a very long to be able to deal with such an intense loss.
“My mother died when I was very young. I didn't want to be in the position I was in, but I eventually pulled my head out of the sand, started listening to people and decided to use my role for good," Harry told Levin. "I am now fired up and energized and love charity stuff, meeting people and making them laugh."
“I sometimes still feel I am living in a goldfish bowl, but I now manage it better. I still have a naughty streak too, which I enjoy and is how I relate to those individuals who have got themselves into trouble.”
Harry's causes range from those that carry on his mother's work (he co-founded an HIV charity in Africa and works to clear land mines like Diana did so many years before) to ones that he's passionate about, like supporting wounded veterans.
Harry took what he saw during his meetings with injured vets and decided to create the Invictus Games, a series of sports competitions similar the Olympics. The Invictus Games, which began in 2014, travels to Toronto this September, and then to Australia in 2018.
Another quality Diana instilled in her boys was the importance of living as ordinary a life as they could, despite their station.
“My mother took a huge part in showing me an ordinary life, including taking me and my brother to see homeless people. Thank goodness I’m not completely cut off from reality," he explained. "People would be amazed by the ordinary life William and I live. I do my own shopping. Sometimes, when I come away from the meat counter in my local supermarket, I worry someone will snap me with their phone. But I am determined to have a relatively normal life, and if I am lucky enough to have children, they can have one too.”
In a brotherly burn to William, Harry cheekily added, “Even if I was king, I would do my own shopping.”