Princess Diana’s older sisters may be blamed for her and Prince Charles’ failed marriage from 1981.

In the book “The Duchess: The Untold Story,” royal author Penny Junor said that the Princess of Wales told her sisters the day before her royal wedding to Prince Charles that she doesn’t want to push through with their nuptials. At that time, Princess Diana already knew that Prince Charles was having an affair with Camilla Parker Bowles.

“Diana had qualms. She’d told her sisters the day before that she couldn’t go through with it now that she knew that Charles was having that last lunch with Camilla,” Junor said.

But Princess Diana’s sisters told her that she could no longer chicken out from the wedding because her face had already been printed on several souvenir items.

“They may have been making light of it, but they were right. This was not a simple family wedding with a hundred or so friends to disappoint… This was a full-blown state occasion,” Junor said.

Since Princess Diana didn’t receive any support from her sisters to cancel her wedding to Prince Charles, she pushed through with it. But after just 11 years, the couple ended up in a separation. Their divorce was finalized in 1996.

Meanwhile, Princess Diana’s wasn’t the only one who had reservations about the royal wedding. Prince Charles wasn’t also sure about tying the knot with the mom of two but he knew that there was no other way out.

Prince Charles hoped that things would get better between him and Princess Diana but things just got worse. The night before their nuptials, Prince Charles her Princess Diana a note along with a signet ring that bore the Prince of Wales’ feathers.

In the note, the future King told Princess Diana that he was very proud of her and vowed to be at the end of the altar when she walks by.

Prince Charles, Prince William, Princess Diana
Pictured: Prince Charles, Prince William, Princess Diana in the gardens of Kensington Palace. Getty Images/Hulton Archive