Although he is generally referred to as Prince William, or Your Royal Highness, Prince William does have a last name. Things are different for the British Royal Family, and they usually don’t use a last name, but they do have them for official paperwork.

All descendants of Queen Elizabeth, Prince William included, use the last name Mountbatten-Windsor. Windsor is the late Queen Elizabeth’s last name, combined with the late Prince Philip’s last name, Mountbatten, and the decree stands since 1917, when George V shook things up and decided all male descendants would use the surname Windsor — which also applied to Queen Elizabeth.

However, in the Royal Family, family titles also hold the place for last name, and William often used the surname Wales, after their father, the Prince of Wales, while at school, at the university, and in the army. After marriage, the two Royal brothers received other titles, the Duke of Cambridge for William, and the Duke of Sussex for Prince Harry. Now, Prince William is officially the Prince of Wales, which means he continues to use his previous surname.

Similarly, Prince William’s children also use the last name “Wales.” The little ones are known at their school, Lambrook, as George Wales, Charlotte Wales, and Louis Wales. Meanwhile, Meghan and Prince Harry’s children, Archie Harrison and Lilibet Diana, use the last name Mountbatten-Windsor. However, a last name isn’t as common for the Royals as for the common folk, so they probably don’t spend too much time thinking about it.