Monarchs can stick with their first name or branch out and pick a new name.
Now the conversation has turned to what William, Prince of Wales will someday choose as his regnal name.
However, there’s an ongoing consensus that William will use his first name due to its positive association.

As king, William could continue his legacy under the same name
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“When he launched Earthshot he was the Duke of Cambridge, but he called himself Prince William.”
William’s work with Earthshot has given him the opportunity to visit the U.S. twice in two years.

In addition, William is also pledging to conduct his royal duties in a more hands-on manner.
In addition, the name is also one of Charles' ownroyal middle names.
William’s other middle names also have familial connections.

The prince, however, diffused the question with a laugh and opted not to answer.