The strained relationship between Prince William and Prince Harry, which has been in the spotlight since the Duke and Duchess of Sussex stepped down from their royal roles in 2020, may have begun much earlier than previously thought, according to a royal biographer.

Robert Lacey, author of the best-selling book "Battle of Brothers," claims that the two princes have had arguments dating as far back as 2002, suggesting that their current rift is not solely a result of Harry's decision to leave the royal family.

In his book, Lacey writes, "Meghan was not the original factor in Prince Harry's decision to get shot of his family. In January 2005 following the 'Colonials and Natives' costume fiasco, we now know that Prince Harry was drawn to re-evaluate his elder brother's involvement and the unfairness of William's emergence smelling of roses. It made Harry feel alienated. Friends recall 'no speaks' and quite a serious rift between the brothers at the time - as there had been after the 'Drugs Shame' of 2002, when Harry had first started to realise the price of playing the functional scapegoat."

The revelation of the brothers' long-standing tensions comes amidst the recent announcement by the Princess of Wales, Kate Middleton, that she has been diagnosed with cancer. While some had hoped that this news might lead to a brief reunion between the brothers, sources close to the Prince and Princess of Wales suggest that a reconciliation is unlikely, even if Harry visits the UK in May to celebrate the 10th anniversary of the Invictus Games, as reported by New York Post.

Insiders told the Telegraph that with both Middleton, 42, and King Charles III battling cancer, their "Harry problem" is the last thing on their minds. Sources say that Prince William, 41, "has always done all he can to protect his family," and will do whatever it takes to maintain his wife's privacy throughout her treatment.

In response to the Princess of Wales' health news, Prince Harry and Meghan Markle shared a short statement, saying, "We wish health and healing for Kate and the family, and hope they are able to do so privately and in peace." ITV's royal editor, Chris Ship, also revealed that Prince Harry had "reached out to his brother" after learning of Kate's cancer, and that both Harry and Meghan had been in touch with their brother and sister-in-law privately.

Despite these gestures, royal expert and author Tom Quinn believes that any potential meeting between the brothers during Harry's rumored UK visit in May would be brief and carefully choreographed. "Given Kate's cancer diagnosis, Harry will certainly make efforts to see his brother and Kate when he returns to the UK in May - if it happens at all it's to be a very brief carefully choreographed meeting and organised to last a short time so that the brothers can avoid any difficult conversations," Quinn told the Mirror.

The Duke and Duchess of Sussex's sensational decision to step down as senior members of the royal family in 2020 has further strained the relationship between the brothers. Should Meghan Markle join her husband on his upcoming travels to England, it would be her first time back since the late Queen Elizabeth II's funeral in September 2022. However, the couple's loss of taxpayer-funded UK security protection may make it tricky for them to return together, as they will now have to pay out of pocket for their family's security when visiting the UK.

As the royal family faces multiple health challenges and ongoing tensions, the prospect of a genuine reconciliation between Prince William and Prince Harry seems increasingly remote. The brothers' long-standing rift, which predates Harry's departure from the royal family, appears to have created a gulf that may prove difficult to bridge, even in the face of personal and familial adversity.