Prince William 'left furious after Prince Harry and Meghan Markle's slight' in get well soon card

They added that William was particularly annoyed the Sussexes called his wife "Kate" when "they were sending her get well soon messages after her cancer diagnosis".

The insiders claimed that Harry and Meghan’s decision to call the Princess of Wales "Kate" was "an entirely unnecessary and deliberate irritation".

It could also explain why the Prince and Princess of Wales did not publicly respond to the Duke and Duchess of Sussex's well wishes.

"Catherine" is understood to be the name her friends and family use, and the name William uses in private.

It is also how the Princess of Wales introduces herself to others.

Although she was widely known as "Kate" at school and university, she made a deliberate switch to her full name, Catherine, shortly before marrying William.

In Harry’s book, Spare, he always refers to the Princess of Wales as "Kate".

A source claimed to the Daily Beast that Prince William was annoyed when Harry and Meghan chose to refer to the princess as "Kate" in a March 2024 statement, released after the princess announced her cancer diagnosis.

The brief statement said: "We wish health and healing for Kate and the family, and hope they are able to do so privately and in peace."

A friend of the Prince and Princess of Wales's said: "The fact that Harry and Meghan were unable to bring themselves to use her chosen name, even when they were sending her get-well-soon messages after her cancer diagnosis, was noted.

"William takes offence at people calling Catherine 'Kate', because she has asked to be known as Catherine.

"It’s a fairly simple wish to respect. I’m sure Meghan wouldn’t like it if William started publicly calling her 'Meghan Markle'.

"Of course, it’s an utterly trivial thing, but those of us who know William know that it is one of the things that pushes his buttons.

"Pushing his buttons while he was going through his wife’s cancer seemed an entirely unnecessary and deliberate irritation.

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"I wonder if the private card began, 'Dear Kate…'"

Another friend of the Waleses said: "No one’s saying it’s responsible for all the trouble, but deliberately calling someone by a name they don’t like is just bl**dy rude.

"If Harry and Meghan were serious about healing their issue, a good first step would be to call her Catherine."

GB News has contacted Kensington Palace and the Sussexes' press secretary for comment.