The Queen Mother was an important fixture in Prince Charles’ life. In fact, while the heir to the throne was having doubts about his relationship with Princess Diana, the late royal was the one who encouraged him to go on with it.

In the book “The Firm,” royal author Penny Junor said that the Prince of Wales had some serious doubts about the future of his relationship with the Princess of Wales. As such, he sought the advice of his family, friends, and official advisers.

Prince Charles wanted to make sure that his marriage to Princess Diana would last. And he also knew that he couldn’t afford to make a mistake with his decision. During this difficult time, it was the Queen Mother’s advice that struck a chord with the future King.

“Most people counseled for the marriage – including, significantly, the Queen Mother. She was very keen on the match; Diana was the granddaughter of her friend and lady-in-waiting, Ruth, Lady Fermoy, and in every sense, on paper, a perfect match,” Junor said.

The Queen Mother’s former lady in waiting reportedly knew that Prince Charles and Princess Diana weren’t a perfect match. However, she chose to keep quiet.

Prince Charles proposed to Princess Diana in 1981, and they tied the knot on July 29. Unfortunately, their marriage didn’t last. In 1992, the Prince and Princess of Wales announced their separation. And by 1996, their divorce had already been finalized.

According to Junor, Fermoy apologized to Prince Charles for not warning him about Princess Diana.

“Diana, she knew, had been a ‘dishonest and difficult girl.’ Her father, who died in 1991, also admitted he had been wrong not to say something,” Junor said.

Meanwhile, it didn’t also take very long for the Queen Mother to change her mind about Princess Diana. The mother of Queen Elizabeth II previously branded Prince Charles’ ex-wife a silly girl. Princess Diana asked the Queen Mother about Prince Charles and Camilla’s affair years ago, but the Queen Mother said that the mom of two was being silly.

Prince Charles and Princess Diana
Prince Charles and Princess Diana are pictured at an official event during their first royal Australian tour 1983 in Newcastle, Australia. Patrick Riviere/Getty Images