The best thing about the drama surrounding the Royal Family is that the royals almost never address it directly even when fans know that something is definitely brewing behind the scenes - thereby adding an element of mystery.

However, a brand new book by author Tom Quinn, titled 'Kensington Palace: An Intimate Memoir From Queen Mary To Meghan Markle', aims to reveal what royals are actually like behind the curtains. In order to add credibility to his work, Quinn made sure to talk to several former staffers from Kensington Palace. In fact, some of them had even worked at the royal residence when the Duke and Duchess of Sussex were living there before tying the knot.

Sources opened up to Quinn about the differences between Meghan Markle and her sister-in-law Kate Middleton and recounted one alleged incident that eventually forced the Sussexes' to consider moving to Windsor and split from the Duke and Duchess of Cambridge, according to an excerpt from the book published by the Daily Mail.

"Kate is actually one of the nicest royals, and she hasn't let life in her extremely grand apartment at Kensington go to her head—or at least not too much," one insider told the author. "She is nice to her staff, in the main, and she was very warm towards Meghan when she arrived."

Meghan was allegedly green with jealousy about her and Harry's lower position in the pecking order as compared to that of Kate and her husband William, who is set to inherit the throne, according to the source.

"I think she has found that difficult to deal with," the insider continued. "And although Harry loved their cottage in the grounds, Meghan was conscious that it was tiny in comparison to the vast apartment complex where Kate and William live."

Meanwhile, a former palace servant agreed with the previous source and told Quinn about the incident that finally led the Sussexes to split their household from the Cambridges and depart from Kensington Palace.

"Kate was horrified when Meghan shouted at a member of Kate's staff—that was definitely the beginning of discussions about leaving Kensington Palace," the second source told Quinn. "Like many people not used to dealing with servants, Meghan overdoes the imperiousness; so, on the one hand, she wants to be like Diana, a people's princess, and on the other she wants people to stand to attention when she clicks her fingers."

A third insider who previously worked at Kensington Palace told the author they believe Meghan's rebellious behavior was a result of how the British royal family treated her as a divorced, mixed-race American.

"There are the more reactionary elements in the Royal Family who do look down on her, and she knows it," the insider said. "This makes her overreact sometimes—she doesn't have Kate's assured way of dealing with people."

Palace staff soon understood that Meghan was the dominant one in the relationship between her and Harry. And as time went by and they failed to warm up to her due to her reprimanding nature. In fact, within weeks of her arrival, they already had demeaning nicknames for her. Some of them were, 'Me-Gain', the 'Duchess of Difficult,' 'Di 2', or 'Di Lite'.

With that said, we cannot wait for the full release of 'Kensington Palace: An Intimate Memoir From Queen Mary To Meghan Markle' on May 14.