After Prince Harry and Meghan Markle's wedding and subsequent title change, we got to wondering, "When Prince Charles is king, what will Prince William and Kate Middleton's titles be?" Instead of referring to the couple as the Duke and Duchess of Cambridge — a moniker we've all come to know and love — after Prince Charles is crowned king, the royal couple will inherit new names.
One of Prince Charles' many titles is Duke of Cornwall. He will cede that title to his son after his coronation. Thus, Prince William will became the Duke of Cornwall and Cambridge, and his wife will become Duchess of Cornwall and Cambridge, according to royal historian Marlene Koenig. Prince William will also receive his father's Scottish title, which is Duke of Rothesay. Currently, Prince William's royal title in Scotland is Earl of Strathearn, but it's presumed that he will give that title to his son, Prince George, when he becomes the new Duke of Rothesay.
Even Prince George, Princess Charlotte, and Prince Louis will have to change their names when their grandfather becomes king: They too will add "of Cornwall and Cambridge" to their royal stylings. It's also possible that their last names will change from just "Cambridge." That said, royals don't technically need last names, and it would be hard to find someone who needed a last name to figure out which Prince George you were talking about.
Prince William will also be granted another title according to tradition: Prince of Wales. Prince Charles currently holds that title, but it will return to the crown when he becomes king. But "Prince of Wales" is not a hereditary title; it is granted at the discretion of the monarch. Queen Elizabeth didn't name her eldest son the Prince of Wales until he was nine years old. However, we feel confident that Prince Charles will grant his son the title relatively soon after he takes the throne, as there's no need to wait. When this happens, Kate Middleton will take the title "Her Royal Highness the Princess of Wales."
Does your brain hurt just thinking about all this title swapping? Fortunately, you don't have to worry about any of this as long as Queen Elizabeth is on the throne — so let's cheers to her long life.