Princess Kate has been revealed as a calming influence for her husband Prince William, who can become ‘irritated quickly’ and can be ‘fractious’ at times..

A new book lifts the lid on the behind-closed-doors relationships between the royal family with various servants and close quarter workers divulging intimate information.

Royal staff members have spoken to author Tom Quinn for the new book, Yes Ma’am: The Secret Life Of Royals, and they give a fascinating insight into the down time moments for one of the most high profile couples on the planet.

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“[King Charles and William] both get irritated very quickly,” a former staff member says in the book.

“They are very picky. It comes naturally to them.”

“I don’t know where William would be without Kate — she hasn’t had everything done for her throughout her life, so she calms him down when he gets a bit fractious,” the anonymous former employee said.

The book says the Prince can in the heat of the moment be “prone to tantrums” with insiders saying “he sometimes has to be treated as her fourth child.”

Always under the microscope of public scrutiny, the book goes on to state that the royal couple are able to laugh at their situation and have a lighter side not seen by many.

“She (Princess Kate) insists that as he gets older, William looks more like his great-great-great-grandfather Edward VII and she likes teasing him about the fact that his stepmother, Camilla, is descended from Edward VII’s favourite mistress,” excerpts from the book which have printed in The Times state.

In the early stages of their relationship Princess Kate made a significant fashion faux pas which was greeted with jokes from her husband who according to a staff member joked that she “looked as if she’d just run through a charity shop in superglue”.

A former Kensington Palace maid reportedly told Quinn that “Kate had to explain many of the things that parents outside the royal family do with their children as a matter of course.”

“She had to show him how to give the children a piggyback, for example,” one ex-employee explained.

“William said very quietly, ‘My father never gave me a piggyback.’”

Princess Kate has been hailed as an intelligent, considerate wife and mother who is able to read a room.

“She doesn’t jump in straight away and try to change everything to suit her way of thinking. She bides her time and is very intelligent and intuitive about other people, what they do and how they behave. She was also coached — not just by William, who wanted Kate to avoid the problems his mother had encountered, but also by the staff,” the book states from another palace insider.

“Kate was always happy to accept advice both from the lower staff, with whom she got on very well, and from the courtiers, even though some of them were initially very snooty about her.

“It was the same kind of backbiting gossipy criticism that Meghan had to put up with, but Kate is actually a much stronger person than Meghan in many ways. Yet what Meghan saw as Kate being pushed around, Kate saw as an essential part of being a member of the royal family.”