Royally Cruel: Kate Middleton 'Hurt' After Being Mocked by Prince William’s Friends' 'Cruel' 3-Word Nickname for Future Queen

Catherine, Princess of Wales, is not the first commoner to marry an heir to the British throne, but she could be the only one who endured "casual cruelty" from a future king's pals.

Royal author Katie Nicholl told a source that before their elopement, those in Prince William's circle would whisper "Doors to Manual," which was a quip about Carole Middleton's having worked as a flight attendant in the past. But even their cruelty didn't bring the soon-to-be Duchess of Cambridge down.

"To her full credit, Kate never rose to it — the snootiness of the upper classes leveled at what they called the en-masse Middletons," Nicholl added.

Another source familiar with how the future princess was treated before becoming royal told an outlet, "It was never water off a duck's back, but she has extraordinary strength of character and resilience. I've never once seen or heard of her losing her temper."

The Princess of Wales went through an extraordinary amount of intense media interest in her life during this era, which saw some outlets in the British press label her "waity Katie," implying she was merely toughing out the intrusions solely to become a princess in due course. Although Carole and Michael Middleton ran a highly successful party corporation that made the family millionaires, money and prestige meant nothing when it came to a commoner dating the future king.

In the early 2000s, when Kate and William started dating, there was a strong strain of deference and snobbery that existed in the upper classes in British society that is likely not as well-known now. Although Lady Diana Spencer was technically a commoner when she dated then-Prince Charles throughout 1980, she was a titled aristocrat from one of England's noblest families.

The same is partly true for Queen Camilla, whose mother, Rosalind Cubitt, was the daughter of the 3rd Baron Ashcombe, making Her Majesty the granddaughter of a baron. This meant that Kate would be the first tried and true ordinary citizen to marry a future king in the history of the monarchy. But initial prejudices have likely worn away thanks to the princess' fierce commitment to her family and her royal duties.

Although the future queen may have "suffered in silence," during the mocking as one former palace insider observed, she was never committed to letting anyone "walk all over her."

Some observers see her and William's "occasional" arguments as completely normal. "It’s well known that William can be hot-tempered and certainly quite stubborn. Of course, they have rows, which apparently can be quite fiery, but they are quickly over and peace is restored," royal commentator Jennie Bond told a publication.

However, the Prince of Wales may have inherited his strong temper from the likes of King George V, King George VI, Prince Philip and even his own father's "grumpiness."

Hindustan Times reported on Nicholl's remarks.