Fresh claims about the breakdown of Princess Diana and King Charles III's marriage have emerged in a new memoir by Diana's brother, Earl Spencer, who says the late Princess of Wales once told him she was seeking a divorce because her husband was allegedly "in love with his valet." The allegation appears in Swan Song: Diana, My Sister, Earl Spencer's new book about his sister's life and legacy. According to extracts reported by several media outlets, Spencer recalls Diana informing him that her marriage to the then-Prince Charles was over and claiming that Charles had feelings for a male member of staff.

The claim has attracted significant attention because it revisits long-standing speculation surrounding the troubled royal marriage. There is no public evidence supporting the allegation, and Spencer himself reportedly described the claim as "improbable" when discussing it during a recent BBC interview.

Earl Spencer Defends Inclusion of the Claim

Speaking to BBC presenter Laura Kuenssberg, Earl Spencer was challenged on why he chose to include such a sensitive allegation in the memoir.

According to the interview, Spencer said the comment appeared within the context of a deeply personal conversation in which Diana was explaining why her marriage had ended. He argued that the book was intended as an honest tribute to his sister and that omitting such conversations would have failed to capture the reality of what she was experiencing at the time.

Spencer told the BBC that the conversation was significant because it reflected Diana's belief that her marriage had irretrievably broken down. He maintained that his intention was to document what Diana told him rather than to validate the allegation itself.

BBC Interview: Spencer Doubles Down on Royal Claims

The controversy surrounding the memoir extends beyond the allegation about Charles's personal life.

In the same BBC interview, Spencer strongly defended other explosive claims contained in the book, particularly his account of a phone conversation with the then-Prince Charles following Diana's death in 1997. Spencer alleges Charles said that Diana would be forgotten "soon enough" during a dispute over funeral arrangements.

Buckingham Palace responded unusually forcefully, suggesting that grief can affect memory and judgment. However, Spencer rejected the criticism and doubled down on his version of events.

"I can tell you here and now, those are exactly the words he said," Spencer told the BBC, insisting he was "telling the truth."

He further claimed he had immediately shared details of the conversation with close friends and relatives because he found the remarks so shocking.

A Marriage Long Plagued by Rumours and Infidelity

The marriage between Charles and Diana officially ended in divorce in 1996 after years of public turmoil. Diana herself acknowledged the difficulties of the relationship during her landmark 1995 BBC Panorama interview with Martin Bashir.

In that interview, Diana famously stated that "there were three of us in this marriage," referring to Charles's relationship with Camilla Parker Bowles, now Queen Camilla.

The new allegation revealed by Earl Spencer differs from the narrative that has dominated public discussion for decades, instead focusing on what Diana allegedly confided to her brother during private conversations as the marriage collapsed. Spencer presents the account as Diana's perspective at the time rather than as an established fact.

Renewed Scrutiny Ahead of the 30th Anniversary of Diana's Death

The publication of Swan Song: Diana, My Sister has reignited debate about Diana's relationship with the royal family and the circumstances surrounding her final years.

Spencer has described the book as his final major public account of his sister's life, saying he felt a responsibility to record what he believes to be an accurate historical account. During media appearances promoting the memoir, he has repeatedly defended its contents and insisted that readers are being given an unfiltered account of Diana's experiences as he understood them.