Prince William and Prince Harry have shared a painful regret about their final phone conversation with their mother, Princess Diana, just hours before her death in a Paris car crash on August 31, 1997.

At the time, William was 15 and Harry was 12. The brothers were staying with their father, then-Prince Charles, at Balmoral Castle in Scotland during their summer holiday. They were expected to see Diana the following day after spending several weeks apart and had spoken with her by phone the night before.

Neither brother knew it would be their last conversation with their mother. In the 2017 documentary Our Mother Diana: Her Life and Legacy, both reflected on how briefly they spoke with her. At the time, they were eager to return to playing with their cousins and did not realize what was about to happen.

“If I’d known that that was the last time I was going to speak to my mother, things that I would—the things I would have said to her,” Harry recalled.

He added that he and William still wished Diana were alive and wondered what kind of mother she would be today, as well as the public role she might have taken on.

“There’s not a day that William and I don’t wish that she was still around,” Harry said.

William also remembered being in a hurry to end the call. Although he did not reveal the specific details of their conversation, he admitted that he would have acted differently had he known it was their last chance to speak.

“Harry and I were in a desperate rush to say goodbye, you know,” William said. “‘See you later’…if I’d known now obviously what was going to happen, I wouldn’t have been so blasé about it and everything else.”

Harry confirmed that Diana was in Paris when they spoke. Looking back, he said he regretted how little time they spent talking.

“I can’t really necessarily remember what I said, but all I do remember is probably regretting for the rest of my life how short the phone call was,” the Duke of Sussex said.

Diana’s final hours also included a conversation with Richard Kay, a longtime royal reporter and friend of the princess. He recalled speaking with her that night and described her as being “in quite a good place.”

According to Kay, Diana especially wanted to return to Britain to see her sons. She was also hoping to begin a new chapter in her life and explore a different path beyond the traditional expectations of royal life.

“She was desperate to try and make a fresh start and do something different,” Kay said. “To explore a different kind of royalty.”

Decades later, William and Harry’s memories of that final phone call remain a deeply personal reminder of their loss and the words they wish they had shared with their mother.