Queen Elizabeth II reportedly blamed her own son, Prince Charles, for his failed marriage with Princess Diana.

The Prince and late Princess of Wales had a fairytale wedding, but their relationship wasn't smooth sailing. It is believed that Prince Charles had always been in love with Camilla Parker Bowles and not Princess Diana.

In the documentary "Princes Of The Palace," biographer Robert Lacey revealed that Her Majesty blamed the heir for his and Princess Diana's divorce. "It would be a great mistake to say [the Queen] blamed Diana for what went wrong," Lacey said (as quoted by Express).

"If anything, I believe, that she and her husband Prince Philip put more of the blame on Prince Charles, and Prince Charles of course, as we since discovered, was already committed emotionally to another woman," he explained.

In addition, the documentary revealed that the People's Princess regularly turned to the monarch for emotional support. Princess Diana would reportedly wait until after the Queen finished her appointments on that day to pour her sentiments about Prince Charles.

"Nobody sees the Queen without an appointment, but Diana used to wait until the Queen’s last visitor – if you like – had left," royal correspondent Ingrid Seward revealed.

"Then she'd dash in before the next one, and just cry. She'd say 'everybody hates me, I hate my sister, I hate my mother, I hate my husband', and the Queen – not used to this type of moral confrontation – just didn't know how to handle Diana."

The Queen and Prince Philip favored Princess Diana for this son. In fact, the royal family initially ruled out Camilla for Prince Charles because she was not "aristocratic enough." In addition, they deemed her as a woman with experience.

On the other hand, the Duke of Edinburgh wanted Prince Charles and Princess Diana's marriage to work. He even called the future king "silly" for leaving Princess Diana for Camilla in one of his letters.

"Prince Philip, a man who had given up his naval career to stand in his wife’s shadow, wrote Diana a string of deeply personal letters," historian Sarah Gristwood said on Netflix's "The Royal House of Windsor."

"Never mind how Camilla might felt about that he was being supportive towards Diana and no one knew better than Prince Philip just how hard it was for an outsider to come into the Royal Family."

Prince Charles and Queen Elizabeth II
Queen Elizabeth II blamed his son Prince Charles for his failed marriage with Princess Diana. Pictured: Prince Charles and Queen Elizabeth II arrive for the formal opening of the Commonwealth Heads of Government Meeting (CHOGM), in the ballroom at Buckingham Palace in London on April 19, 2018. Getty Images/Jonathan Brady