The pair -- dubbed "the heir and the spare" from an early age -- have failed to put aside their differences, despite their father King Charles III's cancer diagnosis.And as Prince Harry, the Duke of Sussex, prepares to return to the UK in the coming weeks with his wife, Meghan, and two young children, all eyes will be on whether the brothers are able to repair ties.Diana had made her two cherished boys promise to always stand by one other, but almost 30 years after her death they are no longer talking.The last time they were seen together was in September 2022 at the death of their grandmother Queen Elizabeth II.Even Charles's February 2024 announcement that he was receiving treatment for cancer did not spur a reconciliation between Prince William, 44, and his younger sibling Harry, 41.

William is the eldest son of King Charles III's first marriage to Princess Diana © Johnny EGGITT / AFP/File

With William in the UK and Harry self-exiled in California, the gulf between the two has only widened.A visibly upset Harry said in an emotional February 2025 BBC interview that he missed the UK, and he wanted to reconcile with his family.He and Meghan and their two children Archie 7, and Lilibet, 5, did meet privately with Charles and Queen Camilla in July. It was the first time the children had been with their grandfather since 2022.But Harry has admitted the revelations made in his 2023 controversial biography "Spare" and a devastating TV interview with Oprah Winfrey had rocked relations."Of course some members of my family will never forgive me for writing a book," he told the BBC. He added, however: "I would love for reconciliation."Royal expert Richard Fitzwilliams told AFP he believed William would be "very unhappy" about the news of Harry's return."I think William would be adamantly opposed to this. Because there is a very deep rift," he said."He feels Harry has betrayed him. He's made that clear."'Different paths'In 1997, the nation's hearts went out to the two young boys, then aged 15 and 12, as they accompanied Diana's coffin through hushed London streets at her funeral.Since then, every twist of their relationship has been chronicled by the press.