When it comes to Britain's newest royal, it seems there's no such thing as a sure bet. Until he was born, many were gambling on Prince Harry and Meghan Markle's first child being a girl. Then all bets were on the little boy being named Alexander, James, Arthur or Spencer. But once again, the punters were wrong.

Just hours after the Sussex family had their first photocall at Windsor Castle, the proud parents anounced the name of their newborn on Instagram. He's been dubbed Archie Harrison Mountbatten-Windsor.

Apparently the little tyke's great-grandparents, Queen Elizabeth and Prince Philip, and his American grandmother, Doria Ragland, were present for the special occasion.

The name Archie is derived from Archibald which means "brave" or "bold", while Harrison means "son of Henry" — Prince Harry's real name. 

As for Mountbatten-Windsor, it's the royal family's surname, which is seldom used as most nobles are known by their lengthy formal titles or, if applicable, Prince or Princess (think Prince Harry and Meghan, Duchess of Sussex).