The Queen has a strict rule (open in new tab) that she has always followed: never speak ill of a member of the royal family to outsiders.

Although this is not an official edict, this unspoken rule is important to the Queen, especially as she strives to keep the royal family strong even as the world watches their every move (and endlessly gossips about every feud and bit of drama the royal family experiences).

These rules are outlined by royal author Brian Kozlowski (opens in new tab) in his book "Long Live the Queen! 13 Rules for Living from Britain's Longest Reigning Monarch" (opens in new tab), In "13 Rules for Living from Britain's Longest Reigning Monarch" (opens in new tab), the author guides readers on how to live a happy and successful life by taking tips directly from the Queen herself.

"One of the Queen's unspoken rules is to never speak ill of a family member to outsiders, but rather to be as supportive as possible," writes Kozlowski, and examples of times when the Queen refused to deviate from her supportive attitude, even when it was not the easiest He cites Princess Diana's ongoing drama in the 1990s (opens in new tab) as an example of a time when she refused to deviate from her supportive stance, even when it was not the easiest thing to do.

"Princess Diana may have had an unimaginably difficult life in the 1990s, but during a press conference at the palace, the editor of the News of the World asked if Princess Diana could hire a servant to run errands if she did not want to be followed by the paparazzi. When questioned, the Princess was quick to defend her," he wrote."

"That is the most pompous thing I have ever heard," the queen replied, famously receiving a round of applause from the other editors in the room.

Over the years, several people, including Prince Philip's uncle, Louis Mountbatten (opens in new tab), have noted the Queen's determined support for her family and praised her ability to handle all family dramas and difficulties with grace.

"The more he watched the royal drama unfold," Kozlowski writes, "the more Louis Mountbatten came to believe that the queen's greatest personal achievement was keeping the family together and dealing with the chaos she had brought upon herself. This is even more so given that, as Mountbatten told his confidant John Barratt, "Most people can hide their family problems, but the queen has always been the center of public attention." But what is most important to the queen is always the bigger picture, not individual squabbles with her children, grandchildren, husband, or sister. The Queen still believes, as did her mother, that "the unity of the family is the strongest in the world."