As far as we're concerned, Princess Diana did a wonderful job naming her boys. It's hard to picture Prince William or Prince Harry with any other names, but in her book, Diana admitted that if Prince Charles had gotten the last word that would have been the case.
So what were the names Diana nixed because she considered them "too old?" Well, in Andrew Morton's book Diana: Her True Story, which he wrote with Diana herself, Diana says Charles wanted to go with Albert and Arthur.
“I chose William and Harry, but Charles did the rest,” "The People's Princess" said. “He wanted Albert and Arthur, and I said no. Too old!”
Now there's nothing wrong with Albert or Arthur per se, but we definitely see what Diana was thinking. For example, Prince Albert of Monaco — Grace Kelly's son — is maybe the most famous living Albert and he's 59 years old. That's not super old by any stretch of the imagination, but it's a far cry from Prince William's 35 years or Prince Harry's 32.
Fortunately, and obviously, Diana won out, but Prince Charles still found a way to insert his preferences. Prince William's full name is William Arthur Philip Louis, and Prince Harry's full name is Henry Charles Albert David.
If William, for whatever reason, doesn't like his name, there's an odd rule in place in Britain that would allow him to change his name when he becomes king. Prince Charles is expected to change his regnal name to King George VII if and when he takes over from Queen Elizabeth. That said, not all royals change their name. Queen Elizabeth is an example of a monarch who chose to keep her Christian name.