Prince Louis was almost given a completely different title due to strict royal rule

Despite being the youngest son of Prince William and Kate Middleton, the Prince and Princess of Wales, Prince Louis nearly had a different title.

There are many different weird and wonderful rules when it comes the Royals and their naming protocols.

The Mirror reports that Louis, the youngest child after his older siblings, Prince George and Princess Charlotte, wasn't initially automatically given the title of Prince.

The rule dates back to the reign of King George V.

This rule meant that an HRH title, e.g His/Her Royal Highness, was only awarded to those 'closest to the top of the line of succession'.

Such examples would be the monarch's children and grandchildren, and they had to be born through the male line.

Louis was born during the late Queen Elizabeth's reign, so wasn't automatically eligible for the title.

An old rule meant that Prince George, Princess Charlotte and Prince Louis weren't automatically given their Royal titles (Karwai Tang/WireImage)

Nor, it turns out, were Charlotte and George, and Her Majesty had to change the rules for them too.

If the late Queen hadn't made the amendments, Louis would have been Master Louis Cambridge or Master Louis Windsor.

The same scenario also happened to Prince Harry and Meghan Markle when they welcomed their son, Archie.

In the bombshell interview with Oprah, Markle shared her fears that the Queen wouldn't bend the rules for their son in the same way.

Her fear was, that if Archie also wasn't eligible for the Prince title, that he wouldn't get the security to match.

She said: "They were saying they didn't want him to be a prince or princess, which would be different from protocol, and that he wasn't going to receive security. This went on for the last few months of our pregnancy where I was going, hold on for a second. They said [he's not going to get security], because he's not going to be a prince."

Prince George and Louis have their late great-grandmother to thank for their titles (Max Mumby/Indigo/Getty Images)

Markle added: "Okay, well, he needs to be safe so we're not saying don't make him a prince or princess, but if you're saying the title is what's going to affect that protection, we haven't created this monster machine around us in terms of clickbait and tabloid fodder you've allowed that to happen which means our son needs to be safe."

Archie and Lilibet gained royal titles when King Charles took the throne, as they are sixth and seventh in line to the throne.

Prior to his ascension, they went by Master Archie Mountbatten-Windsor and Miss Lilibet Mountbatten-Windsor.

The Sussex couple issued a statement: "The children's titles have been a birthright since their grandfather became monarch. This matter has been settled for some time in alignment with Buckingham Palace."