Britain's feuding princes, William and Harry, will put their differences aside on Thursday to attend the unveiling of a statue to their late mother Princess Diana on what would have been her 60th birthday.
For most of their lives, the royal brothers have been close, united by the shared trauma of losing their mother who died aged 36 in a 1997 Paris car crash when William was 15 and Harry 12.
But since Harry's 2018 wedding to his American actress wife Meghan, relations between them have soured and an explosive interview that the couple gave chat show host Oprah Winfrey in March marked a new low.
In it, Harry, now 36, criticised his father Charles and said William, 39, and the family were trapped, while the couple accused one unnamed royal of making a racist remark.
Biographer Robert Lacey said that in April the brothers quarrelled in the immediate aftermath of the funeral of Prince Philip, their grandmother Queen Elizabeth's husband of more than 70 years, and there was no sign of any improvement.
"The conflict between Diana's two bitterly divided sons does not seem likely to end any time soon," he wrote in the Daily Mail, adding that friends and family were trying to forge a reconciliation.
This week's unveiling in London of the statue, which the princes commissioned four years ago to celebrate Diana's life, provides a rare opportunity for such a rapprochement, with Harry returning from his new home in the United States.
"Unless one of them is going to say sorry, and I think that probably has to be Harry, I can't see this relationship at the moment mending itself," royal commentator Penny Junor said.
"My understanding is the boys are not speaking to one other, certainly not in the way brothers normally speak," she told Reuters.
Harry told Winfrey that their relationship was "space at the moment", but hoped time would heal it.
"I love William to bits, he's my brother, we've been through hell together and we have a shared experience. But we're on different paths," he said.
Thursday's statue unveiling in the Sunken Garden at Kensington Palace where Diana lived, and which is now home to William and his family, will be a small event with the princes, Diana's close family and the sculptor Ian Rank-Broadley among the few attending.
The Daily Telegraph reported that William would take his wife Kate and their three children George, Charlotte and Louis, for a private viewing of the statue before its official unveiling as they will not be present on the day.
Almost a quarter of a century since her death, Diana continues to captivate.
British newspapers regularly pore over her life and the circumstances surrounding her death, while the disclosure last month that a BBC journalist lied to secure a sensational 1995 interview in which she admitted to an affair and shared details of her failed marriage to Charles, made headlines.