Royal biographer Ingrid Seward makes claims about the lead up to the Princess of Wales’ nuptials in her new book, “My Mother And I”

Princess Diana and now-King Charles at their July 1981 wedding day. Photo: Terry Fincher/Princess Diana Archive/Getty

Princess Diana’s father, Earl Spencer, helped convince her that she shouldn’t call off her wedding to then-Prince Charles, according to claims in a new book from a royal biographer.

An excerpt from Ingrid Seward’s new book My Mother And I, published by the Daily Mail this weekend claims that “a month to go until she married the heir to the throne” during her July 1981 wedding, Princess Diana attended Prince Andrew’s 21st birthday at Windsor Castle and was hoping to dance with her fiancé, Prince Charles.

As Elton John performed at the gathering, the now-King Charles “spent the entire evening dutifully working the room and making sure he spoke with as many people as possible,” Seward wrote.

“Diana was in despair. Her fiancé had been away in America for most of the previous week, yet he clearly had no desire to dance with her,” the excerpt continued. “Feeling emotionally drained, she threw herself into dancing frantically with one man after another — and finally just dancing by herself.”

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Princess Diana Cardiff appears at Cardiff International Arena for ‘A Concert of Hope’.Tim Graham Photo Library via Getty Images

Prince Andrew’s 21st birthday party took place in June of 1981, and, per Business Insider, Elton John described it in his 2019 memoir “Me” as “the world’s quietest disco,” explaining that nobody wanted to offend Queen Elizabeth, who was present.

Meanwhile, according to Seward, at one point during the evening, footman Mark Simpson spotted Princess Diana “looking exhausted and lost in her thoughts yet still moving in slow, rhythmic time to some tune in her head” in the castle quadrangle.

The excerpt then claims that Princess Diana made her way to her father’s home in Northamptonshire at 5:30 a.m. after the party, feeling “distraught, flustered, angry and had no intention of ever going back. As far as Diana was concerned, the Royal Wedding was off.”

“But when she explained her decision to her father, Earl Spencer, he was appalled,” the author continued. “After calming her down, he pointed out it would be an act of gross discourtesy to break off her engagement to the future King so close to the wedding.”

“And, anyway, wasn’t it what she’d always wanted? Didn’t she remember him telling her that she should only marry a man she loved – and her firm reply: ‘That is what I am doing’? Diana wasn’t immediately convinced,” Seward added.

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In the Daily Mail excerpt of My Mother And I, Seward goes on to claim that, eventually, after “gusts of tears and spells of indecision,” Princess Diana “allowed her father to talk her round.”

“She couldn’t deny that she still wanted to be the Princess of Wales. And, at 19, she was young enough still to believe in happy endings, despite what her instincts had told her on that terrible night,” Seward wrote.

My Mother And I tells the story of King Charles and his mother, the late Queen Elizabeth, and is released on Feb. 15 via Simon & Schuster. Later in the excerpt published this weekend, the author also writes about Princess Diana’s relationship with the late monarch, claiming that those who knew her found Diana “enchanting,” and that Queen Elizabeth “had just two reservations.”

“She wondered whether anyone that young could differentiate between the man and the prince,” Seward wrote. “And she couldn’t help thinking that the Spencer girl would be far better suited to her younger son, Andrew.”

Princess Diana and now-King Charles on their wedding day in 1981. Anwar Hussein/Getty
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Eventually, according to the author, the Queen invited the couple to Birkhall on the Balmoral Estate, where the biographer claims Diana “looked marvelous, very relaxed and quite thrilled with herself.”

Diana and King Charles eventually wed on July 29, 1981 at St. Paul’s Cathedral in London, five months after announcing their engagement on Feb. 24, 1981. The pair would ultimately divorce in 1996, a year before Diana died in a car crash in Paris.

The wedding itself saw the largest TV audience for a wedding of 750 million people in 74 countries, as previously reported.

Princess Diana later spoke to Andrew Morton about the wedding for his 1992 book, Diana: Her True Story in Her Own Words. “I remember being so in love with my husband that I couldn’t take my eyes off him,” she told Morton. “I just absolutely thought I was the luckiest girl in the world. He was going to look after me.”

In an excerpt from Lady Colin Campbell’s The Real Diana, published in 1998, Diana again described the nuptials: “It was heaven, amazing, wonderful, though I was so nervous when I was walking up the aisle that I swore my knees would knock and make a noise.”