What surname will Harry and Meghan's royal baby have?

Baby Sussex has arrived!

The Duke and Duchess of Sussex welcomed a 7 lb 3 oz baby boy on Monday, May 6. In a short BBC interview, Prince Harry said the couple were “over the moon” and that they have yet to choose a name for their son.

While royal watchers continue to speculate on the first name the baby boy will have, there’s also been questions about what last name he will have.

It’s a complicated matter, but it’s all down to whether the baby will have a title.

Currently, none of Harry and Meghan’s children will be a prince or princess, unless the Queen steps in.

Titles within the Royal Family are limited under the provisions of the 1917 Letters Patent issued by the Queen’s grandfather King George V. This stated: “…the grandchildren of the sons of any such Sovereign in the direct male line (save only the eldest living son of the eldest son of the Prince of Wales) shall have and enjoy in all occasions the style and title enjoyed by the children of Dukes of these Our Realms.”

While the Duke and Duchess of Cambridge’s first born George was always set to be a prince (as he is the eldest son of the eldest son of the Prince of Wales), their daughter Charlotte would have been known as Lady Charlotte without the amendment.

The Queen issued a new letters patent in 2012 so that all children of the Duke and Duchess of Cambridge would be a prince or princess and given the HRH title.

Her Majesty could decide to do the same for Harry and Meghan’s children, but at this point, they will be a lord or lady.

When it comes to surnames, all descendants in the male line of the monarch, other than females who marry or have married, use the last name Windsor, as set out in the Letters Patent 1917.

The Duke of Edinburgh wasn’t able to pass his surname to his children. He had hoped that when his wife took the throne, his adopted last name, Mountbatten, would become double-barrelled with Windsor, but that was not agreed to by then-Prime Minister Winston Churchill.

But a declaration made by the Queen in Privy Council in 1960, said that male-line descendants of the monarch, without royal styles and titles, shall bear the name Mountbatten-Windsor.

If Harry and Meghan’s child is not issued a title, they will carry that last name.

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When the Earl and Countess of Wessex had their first child Lady Louise in 2003, she would have been entitled to be styled as Her Royal Highness Princess Louise of Wessex, as she is a child of one of the monarch’s sons.

However when Edward and Sophie were married in 1999, it was announced that their children would be styled as the children of an earl, rather than as prince or princess.

So while her full name is Louise Alice Elizabeth Mary Mountbatten-Windsor, she is styled as Lady Louise Windsor.

The Royal Family’s website adds: “For the most part, members of the Royal Family who are entitled to the style and dignity of HRH Prince or Princess do not need a surname, but if at any time any of them do need a surname (such as upon marriage), that surname is Mountbatten-Windsor.”

Princess Anne was the first royal to use the surname on her marriage certificate at her wedding to Captain Mark Phillips in 1973.