Queen Mother wanted Charles and Diana to find some space for Camilla in their marriage

Princess Diana shocked the world when she made this remark about her marriage with Prince Charles and his extra-marital affair with Camilla Parker-Bowles: "Well, there were three of us in this marriage, so it was a bit crowded." However, her grandmother-in-law, The Queen Mother, did not see the problem and couldn't understand why the Princess of Wales was not able to make it work with her "favourite grandson."

According to a new Channel 5 documentary "The Queen Mother: Grandmother to the Nation" which aired on Saturday, Queen Elizabeth didn't understand why Charles couldn't stay married to Diana while continuing an affair with his now-wife Duchess Camilla, reports Mail Online. The late royal kept hoping that Charles and Diana would find some space for Camilla in their marriage, a "miscalculation" on her part as she didn't understand it was no longer acceptable in their world.

Royal author Tom Quinn explained in the documentary that some members of the royal family also agreed that the Queen Mother was "meddling in things she didn't understand.

"Diana's grandmother (Baroness Fermoy Ruth Rochie) was a great friend of the Queen Mother and they cooked up the marriage between them. She discussed the whole Camilla business and didn't understand why she couldn't find accommodation with his wife that meant they didn't have to get divorced. But she miscalculated because it was no longer something that would work well in the world Charles inhabited," Quinn explained.

"The Queen Mother thought Diana has a sort of fairytale view of how relationships should be, and conduced and was quite impatient thinking she should grow up," he added. He also claimed that The Queen Mother considered her eldest grandson the "gentlest and kindest of men and a considerate husband" and couldn't comprehend what Diana was complaining about.

Royal expert Richard Kay believes that the reason The Queen Mother favoured Charles so much was that he reminded her of her late husband King George, who was lacking in confidence and needed to be built up. She also felt that she could maintain influence in the family through Charles.

According to BBC Royal Correspondent Jennie Bond, Diana found The Queen Mother "frightening and intimidating," even though they initially enjoyed a close relationship since the royal played a key role in her marriage with Charles. Their relations worsened in 1992, when the Princess of Wales gave details about her tumultuous marriage to Andrew Morton for his tell-all book "Diana: Her True Story."