Prince Harry was asked to be introduced as “Harry” instead of “Prince Harry” or “The Duke of Sussex” at a sustainable tourism summit last week, and now people aren’t sure what to call him.

The Duke of Sussex will stop using his HRH title after he officially resigns from the royal family in April, so it’s likely there will be more events where he is referred to on a first-name basis.

It’s not been made clear whether he will start using a last name – here’s what it could be if he decided to use one.

‘Harry’ isn’t actually his real name – but ‘Duke of Sussex’ is

“Harry” is actually a nickname for “Henry,” although the prince has never used the name.

His full name is: His Royal Highness Henry Charles Albert David Duke of Sussex, as written on baby Archie's birth certificate in May 2019.

While Harry plans to stop using the HRH title in his name from April, he will remain the Duke of Sussex.

Prince Harry

Foto: Prince Harry. Source: Jack Hill - Pool/Getty Images

Therefore, his name could change to "Henry Charles Albert David Duke of Sussex" or "Harry, Duke of Sussex" for short.

This style is similar to that used by other royals who dropped their titles. For instance, when Princess Diana and Prince Charles divorced in 1996, she did not revert back to the name Lady Diana Spencer, as she was previously known. Instead, she became "Diana, Princess of Wales."

However, since Harry appeared not to want to be introduced using his title at the summit last week, it's possible that he won't use it. Alternatively, he could remove "duke" and just be known as Harry Sussex.

This wouldn't be unusual for the prince. He was previously known as "Harry Wales" during his school days and throughout his time in the British Army, after his father, the Prince of Wales.

He could also use the royal family's official last name, 'Mountbatten-Windsor'

While "Wales" was used in instances when the royal needed a last name growing up, he technically never had one.

The royal family's official last name is "Mountbatten-Windsor," however Harry and Meghan Markle never had to use it before because they had HRH titles.

It's a combination of Prince Philip and Queen Elizabeth's last names, with "Mountbatten" from Phillip's side and "Windsor" being the official name of the House of George V's descendants.

Queen and Prince Philip coronation

Foto: Queen Elizabeth and Prince Philip. Source: The Print Collector/ Getty Images.

"It was therefore declared in the Privy Council that The Queen's descendants, other than those with the style of Royal Highness and the title of Prince/Princess, or female descendants who marry, would carry the name of Mountbatten-Windsor," a statement on the royal website reads.

Harry gave the last name to his son, Archie Harrison, who does not carry a title but instead is referred to as "Master Archie."

Therefore, it's likely Harry and Markle could decide to adopt this name, not only because they will now be eligible to use it, but also because it means they will carry the same name as their son.

Until April 1, however, we won't know for sure what the couple intend to be called moving forward.

In the meantime, it seems most appropriate to call him"Harry, Duke of Sussex" - or, as he requested, simply "Harry."

Read more:

Prince Harry was introduced to the stage as 'just Harry' instead of The Duke of Sussex at his first UK engagement since 'Megxit'

Here's what you should call Meghan now that she doesn't go by 'Markle' or 'The Duchess of Sussex'

Here's why Princess Beatrice will become a 'Countess' after her royal wedding, not a 'Duchess' like Meghan Markle