Before the birth of Prince William’s children, Queen Elizabeth II made a significant move to reverse a historic royal rule—one that ultimately influenced the title and name of Prince Louis.

Prince William and Kate Middleton welcomed their youngest child, Prince Louis Arthur Charles, on April 23, 2018. His name paid tribute both to the Queen’s cousin and to Prince Charles, now King Charles III.

William and Kate, now the Prince and Princess of Wales, have three children: Prince George, Princess Charlotte, and Prince Louis. But prior to Louis’ birth, the late Queen took it upon herself to change a rule originally imposed by her grandfather, King George V.

Queen Elizabeth’s decision to revise a long-standing royal protocol

In 1917, King George V established a rule to regulate royal titles. Under this rule, only the children and male-line grandchildren of the reigning monarch were automatically entitled to the titles of Prince or Princess and the style of His/Her Royal Highness (HRH).

This meant that royal great-grandchildren were generally excluded—unless they were the eldest son of the eldest son of the Prince of Wales. If the rule had remained in effect today, it would have applied only to Princes William and Harry, not to their children, such as Prince Louis or Princess Charlotte.

But in 2012, Queen Elizabeth II issued a new Letters Patent that overturned this century-old regulation. Her revision ensured that all children born to Prince William, the eldest son of Prince Charles, would carry HRH titles and be known as Prince or Princess. Without this change, only Prince George would have received such titles, while Charlotte and Louis would not.

Because this update didn’t include all great-grandchildren, Prince Harry’s children, Archie and Lilibet, were not given HRH or prince/princess titles at birth. At that time, Queen Elizabeth II was still the monarch, and her rule only extended the titles to William’s children.

When Charles became king in 2022, the rule shifted again. As Archie and Lilibet were now grandchildren of the reigning monarch, they automatically qualified for the titles of Prince and Princess.

Prince Louis’ name and title would have been entirely different without the Queen’s intervention

Had Queen Elizabeth not changed the rule, Prince Louis’ name and title would have taken a different form altogether.

Instead of being known as Prince Louis, he would have been referred to as Master Louis Cambridge or Master Louis Windsor.