Prince Philip acted rudely during Prince Charles’ confirmation.

On Monday, Prince Philip celebrated his 98th birthday. The Duke of Edinburgh is rarely seen following his retirement in 2017. In fact, he skipped the Trooping the Colour on Saturday.

Back in 2000, it was reported that Prince Philip behaved in a “[explicity] rude” manner during his son Prince Charles’ first confirmation service. He snubbed the event by doing something else during the ceremony.

“Prince Philip conspicuously read a book during Prince Charles' confirmation,” royal correspondent James Whitaker said.

“The Archbishop of Canterbury at the time, Michael Ramsay said: ‘[explicit] rude!’”

It wasn’t the only time Queen Elizabeth II’s husband was accused of being rude. In the 2016 documentary “Prince Philip – A King Among Princes,” he reportedly cracked an “offensive” joke.

Royal correspondent Camilla Tominey revealed that the chef was collecting an award when Prince Philip told him that “no wonder he was a good chef because he was certainly the size for it.” Fortunately, the man was “enormous” and was not offended at all. In fact, he found Prince Philip’s remarks hilarious.

There was also a time when Prince Philip was caught telling a photographer to “just take the [explicit] picture” during a photo-call with war veterans for the Battle of Britain.

According to Tim Heald, Prince Philip defers to Queen Elizabeth II in public because she is the Queen. However, their relationship changes behind closed doors. The Duke of Edinburgh is the boss in their household.

Maltese journalist John Mizzi recalled the time when he heard Prince Philip swore at the Queen.

Heald pointed out that the duke is not afraid to make harsh remarks to the Queen. Her Majesty doesn’t mind and accepts his input because she acknowledges that her husband wears the trousers at home.

The monarch also appreciates what Prince Philip does because he is the only person who can straightforwardly tell her if something is wrong. This makes the two a perfect match.

Tominey said that Prince Philip was a “refreshing change for the Queen” because the people surrounding her often agree with her demands.

Prince Philip and Prince Charles
Prince Philip admitted that he and Prince Charles are very different. Pictured: Prince Philip and Prince Charles listen to speeches before a statue of the Queen Elizabeth, The Queen Mother was unveiled on Oct. 27, 2016 in Poundbury, England. Getty Images/Justin Tallis