Think you know everything about the royal family? Think again. Embarrassingly, most of us have been calling one royal by the wrong name for his entire life.

Prince Harry, the fifth in line for the British throne (Princess Charlotte’s birth demoted his lineage), has captured our hearts with his flaming red hair and mischievous personality. And his dashing good looks and generous spirit don’t hurt, either.

However, there is one important thing we didn’t know about him: Harry isn’t his real name. It’s actually Henry (or rather, Charles Albert David Mountbatten-Windsor)—a common name for English monarchs.

But don’t fret! You’ll only have to use the name if you’re calling Harry by his proper title, His Royal Highness Prince Henry of Wales. Otherwise, he probably prefers his nickname, Harry, which his parents gave him when he was born.

Want to learn more about the British royal family? Check out these fascinating facts about the queen, including the secret behind her purse and why she wears bright colors all the time.