Prince Louis is the youngest child of Prince William and Catherine, Princess of Wales, born into one of the most famous families on earth. And yet, according to royal historians and palace reports, he almost never became a prince at all. Had a single piece of century-old legislation been left untouched, the little boy fans know from balcony appearances might have grown up answering to something far more modest: simply Master Louis.
The reason lies in a rule drafted in 1917, a special intervention by Queen Elizabeth II, and the strange, labyrinthine logic of royal titles that most people never realize exists.
A Rule Born During World War I
In November 1917, King George V issued Letters Patent — formal legal instruments — governing exactly who in the royal family could style themselves His or Her Royal Highness and use the title of Prince or Princess. The timing was no accident. Britain was fighting Germany in the First World War, and anti-German sentiment had made the royal family's German roots deeply unpopular. George V rebranded the dynasty as the House of Windsor and slimmed down royal titles as part of the same national reset.
The new rule limited HRH styles to the children of the monarch, the grandchildren of the monarch through the male line, and the eldest son of the eldest son of the Prince of Wales. Everyone else further down the line of succession would be a lord, lady, or merely an honorific — not a prince or princess.
Why Louis Did Not Qualify
Fast forward to April 2018, and Prince Louis's birth created an unexpected legal wrinkle. At the time of his birth, the reigning monarch was Elizabeth II, his great-grandmother. Under the 1917 rules, only the monarch's children and male-line grandchildren were automatically entitled to princely status. Louis was a great-grandchild — a generation too far.
That means Louis, like his older brother Prince George and sister Princess Charlotte, was born without any automatic right to his famous title. Had nothing changed, he would have carried the plain courtesy style of Master Louis Cambridge or Master Louis Windsor — charming, but a world away from His Royal Highness Prince Louis of Wales.
The Queen's Quiet Fix
In December 2012, months before Prince George was even born, Queen Elizabeth II solved the problem with a new Letters Patent of her own. She extended the HRH title to all children of the eldest son of the Prince of Wales — in other words, to all of William and Catherine's children, current and future. It was a short legal sentence with enormous symbolic consequences, ensuring that George, Charlotte, and Louis would all grow up princes and princesses.
Royal commentators note the decision also had a practical dimension: it corrected an older quirk of the 1917 rules that would have made Charlotte a lady rather than a princess, an inequality widely seen as outdated even then.
The Modern Echo: Archie and Lilibet
The same machinery resurfaced years later with Prince Harry and Meghan Markle's children. When Archie Mountbatten-Windsor was born in 2019, Queen Elizabeth was still on the throne, so Archie was not entitled to be a prince under the 1917 rules. In the couple's interview with Oprah Winfrey, Meghan described being told during her pregnancy that Archie would not receive a title, and she voiced concern that this could affect his security — a claim that fueled weeks of headlines and debate.
Everything changed when Charles III became king in September 2022. As grandchildren of the monarch, Archie and his sister Lilibet automatically became entitled to princely and princely-equivalent styles under George V's century-old framework. The couple confirmed through a statement that the children's titles were their birthright once their grandfather took the throne, and that the matter had been settled in agreement with Buckingham Palace. Overnight, Master Archie became Prince Archie, and Miss Lilibet became Princess Lilibet.
Titles Are Not Decorations — They Are Rules
What the Louis and Archie stories reveal is that royal titles are not gestures of affection or prestige handed out at will. They are governed by precise legal instruments, some more than a century old, written in the language of Edwardian bureaucracy. A child's style can depend on which generation they occupy, which line they descend through, and which relative happens to be sitting on the throne at the moment of their birth.
It also highlights how much quiet authority the monarch holds. A single Letters Patent, issued almost unnoticed in 2012, shaped the public identity of three children who are now among the most photographed young people in the world. Without it, the Wales family would look very different on the palace balcony.
What It Means for Louis Going Forward
Today, Prince Louis is fourth in line to the throne, behind his father, his brother George, and his sister Charlotte. His title is secure for life under the current framework, and when his father becomes king, nothing about his status will change — he will remain a prince as a grandchild of the monarch.
Still, the near-miss remains one of the most fascinating footnotes in modern royal history. The gap-toothed boy whose playful expressions regularly steal headlines at royal events might easily have lived entirely outside the title system, a private citizen with a famous surname. Instead, thanks to a queen's decision made before he was even born, the world knows him as Prince Louis — and every royal watcher knows that a single sentence written in 1917, and another written in 2012, made all the difference.
