The Duchess’ recent revelation has sparked curiosity among Royal Family followers about the official naming conventions for royal children.

Much discussion has taken place this week regarding the complex and sometimes perplexing nature of royal titles, following Meghan Markle’s surprising disclosure in a new interview that she, Prince Harry, and their two children all share the same surname.

This unexpected detail has led some royal enthusiasts to dig deeper into the names and titles of other members of the monarchy—going as far as uncovering Prince Louis’ birth certificate.

Born on 23 April 2018, Prince Louis is the youngest child of Kate Middleton (or ‘Catherine, the Princess of Wales,’ as she is formally known) and Prince William (whose full title at the time of Louis’ birth was ‘His Royal Highness Prince William Arthur Philip Louis Duke of Cambridge’).

Following the passing of Queen Elizabeth II in 2022, William’s title changed, allowing him to use ‘Prince of Wales’ instead of ‘Duke of Cambridge.’

It turns out that Louis’ birth certificate reflects a similar naming pattern.

Obtained by CBS at the time, the official document lists his full name and surname as ‘His Royal Highness Prince Louis Arthur Charles of Cambridge.’ Just like his father, the ‘of Cambridge’ designation could later be replaced with ‘of Wales’ following the Queen’s death.

When signing the birth certificate, Kate mirrored her husband’s title, writing her name as ‘Catherine Elizabeth, Her Royal Highness the Duchess of Cambridge’—a title she has held since their wedding in 2011.

Prince Louis’ formal title follows the same structure as his older siblings—Prince George, 11, and Princess Charlotte, nine.

However, despite their royal status, the children reportedly use the surname ‘Wales’ at school, much like their father William and uncle Harry did during their younger years.

This information about Prince Louis’ full title has left some confused about the naming conventions for the Sussex children.

Meghan Markle and Prince Harry’s son, Archie, was born in May 2019, followed by their daughter, Lilibet, in June 2021.

Although Archie and Lilibet are cousins to the Wales children and grandchildren of King Charles III, they do not hold the same elaborate titles.

In her recent interview with PEOPLE, Meghan, 43, explained that her children do not use the titles ‘His/Her Royal Highness’ at all.

Instead, she revealed that Archie and Lilibet’s official surname incorporates her and Harry’s titles as the Duke and Duchess of Sussex.

She disclosed that they have been using ‘Sussex’ as their family surname for quite some time, explaining that the title was originally granted to her and Harry by Queen Elizabeth II on their wedding day in 2018.

Meghan spoke about the significance of this surname, saying:

“It’s our shared name as a family. And I guess I hadn’t recognised how meaningful that would be to me until we had children. I love that that is something that Archie, Lili, H and I all have together.”

She also expressed how the name is deeply tied to their relationship, adding:

“It means a lot to me. It’s part of our love story.”

However, Meghan’s comments have sparked debate among royal watchers, with some questioning the validity of using ‘Sussex’ as a surname rather than Harry’s legal last name.

One royal fan, as quoted by the Daily Mail, remarked:

“Her name is NOT Meghan Sussex. Her name is technically Rachel Mountbatten-Windsor. Sussex is a county in England & part of a courtesy title—NOT her last name.”

Another critic noted:

“Meghan Markle married Henry Mountbatten-Windsor, not Harry Sussex!”

Before King Charles’ ascension to the throne, Archie and Lilibet originally carried the surname Mountbatten-Windsor. However, following their grandfather’s rise to the monarchy, they became known as Prince Archie of Sussex and Princess Lilibet of Sussex.

Now, they are informally referred to as Archie Sussex and Lili Sussex.