Prince Harry recalls losing Princess Diana in book for children who lost parents amid the COVID-19 pandemic

• Prince Harry, 36, wrote an emotional foreword for a new children's book, "Hospital by the Hill."
• Harry said he "didn't want to believe it or accept it" when Princess Diana died at age 36 in 1997.
• He's compared the media's criticism of Meghan Markle to what Diana experienced after her divorce.

Prince Harry opened up about the death of his mother, Princess Diana, in the foreword of a book written for children who've experienced loss amid the COVID-19 pandemic.

"Hospital on the Hill," written by Chris Connaughton and illustrated by Fay Troote, tells the story of a young person whose mother worked in a hospital and died during the pandemic. The book was released Friday and meant to help bereaved children and adolescents deal with grief.

In the foreword's letter, the Duke of Sussex reflects on the difficulties of losing his mother when he was 12 years old, according to People. Diana died in a car crash in Paris on August 31, 1997.

"While I wish I was able to hug you right now, I hope this story is able to provide you comfort in knowing that you're not alone," Harry, 36, wrote.

"When I was a young boy I lost my mum. At the time, I didn't want to believe it or accept it, and it left a huge hole inside of me," Harry wrote. "I know how you feel, and I want to assure you that over time that hole will be filled with so much love and support."

Harry continued that everyone copes with loss in different ways, but recalling fond memories can bring comfort.

"We all cope with loss in a different way, but when a parent goes to heaven, I was told their spirit, their love and the memories of them do not," Harry wrote. "They are always with you and you can hold onto them forever. I find this to be true."

Harry, who's previously opened up about his mental health struggles after Diana's death, also made a sweet promise.

"You may feel alone, you may feel sad, you may feel angry, you may feel bad," Harry wrote. "This feeling will pass. And I will make a promise to you - you will feel better and stronger once you are ready to talk about how it makes you feel."

"I hope this book helps remind you of just how special your parent or loved one was," he wrote. "And how special you are too."

People reported that the book was published ahead of Britain's National Day of Reflection on March 23. It is being given for free to any young person in the United Kingdom who may be affected.

The book is also promoting services offered by three charities focused on young people and coping with loss: Winston's Wish, Simon Says, and Child Bereavement UK - of which Prince William is a patron.

Prince Harry compared his and Meghan Markle's exit from royal duties to his mother's experience

During "Oprah with Meghan and Harry," the couple opened up about Markle's treatment from the British tabloids while at Kensington Palace. They took a step back from royal duties in January 2020 and have since relocated from the UK to California.

"For me, I'm just really relieved and happy to be sitting here talking to you with my wife by my side because I can't begin to imagine what it must have been like for her [Diana] going through this process by herself all those years ago," Harry told Oprah Winfrey. "Because it has been unbelievably tough for the two of us, but at least we have each other."

Following Diana and Prince Charles' 1996 divorce, Diana faced harsh criticism from the media that has since become a comparison for tabloids' treatment of Markle. At the time of Diana's death, Charles Spencer, the ninth Earl Spencer and younger brother of Princess Diana, said the British press had "blood on their hands" during his eulogy.

In the infamous 1995 BBC interview, Diana shared details about the intense media coverage.

"I seemed to be on the front of a newspaper every single day, which is an isolating experience, and the higher the media put you, place you, is the bigger the drop," Diana said. "And I was very aware of that."

In 2019, Harry said his "deepest fear is history repeating itself."

"I've seen what happens when someone I love is commoditized to the point that they are no longer treated or seen as a real person. I lost my mother and now I watch my wife falling victim to the same powerful forces," the statement read.