Prince Charles was once worried about Princess Diana and Sara Ferguson’s alleged plot against him.

A year before the Prince and Princess of Wales’ divorce, Princess Diana questioned Prince Charles’ suitability as the future king. This led to Prince Charles working himself into a frenzy for fears that his ex-wife and her best friend, Ferguson, were plotting something to have him replaced.

In Tom Bower’s 2018 book “Rebel Prince: The Power, Passion and Defiance of Prince Charles,” the biographer revealed how Prince Charles was so convinced that Prince Diana and Ferguson were trying to block him from becoming the next monarch.

“Now, mindful of Diana’s prediction on ‘Panorama’ that he would never be king, Charles convinced himself that Diana and Sarah, Andrew’s estranged wife, were hatching plans to replace him as heir – by announcing that on the Queen’s death or abdication, Andrew would be Regent until William was 18, when he would take over,” Bower wrote.

The Prince of Wales’ affair with Camilla Parker Bowles only fueled his fears. Queen Elizabeth II and Prince Philip were not supportive of his relationship with the Duchess of Cornwall. In fact, the monarch and Duke of Edinburgh advised him to discontinue their romance.

“After the broadcast, the Queen and Prince Philip – neither of whom Charles viewed as well-meaning advisers – told him that he could not rebuild his image nor dampen the controversy about the succession until he broke with Camilla,” Bower added.

The late Princess of Wales and Duchess of York were very close. A previous report even claimed that Ferguson and Prince Charles’ second wife, Camilla, fought over Princess Diana last summer. Ferguson reportedly couldn’t hold it anymore and confronted Camilla. Prince Andrew’s ex-wife believes Camilla was responsible of Princess Diana’s pain during the latter’s marriage to Prince Charles.

Meanwhile, a number of Britons still don’t want Prince Charles and Camilla to take over the throne after Queen Elizabeth II. Daily Star conducted a poll involving 8,000 people and the majority preferred to skip the Prince of Wales and pass the baton to his son, Prince William. They also wanted Middleton to be the next queen.

However, some have already warmed up to Prince Charles and Camilla. According to those who support the couple, Camilla has already proven herself that she’s worthy to be the next queen consort.​

Prince Charles, Prince Andrew, Prince Edward, Princess Diana and Sarah Ferguson Prince Charles feared and was convinced that Princess Dian and Sara Ferguson were plotting something to replace him as the future king. Pictured: Prince Andrew, Ferguson, Lord Linley, Prince Edward, Prince Charles, Princess Diana, Queen Elizabeth II and Queen Mother outside London Clarence House on Aug. 4, 1989. Photo: Getty Images/Johnny Eggitt