Prince Louis would not have been a prince if the Queen hadn't stepped in to change royal rules
Kate Middleton and Prince William welcomed their baby number three on April 23 and after much wait, we got to know his name and his full title -- His Royal Highness Prince Louis of Cambridge. However, according to Mirror, Prince Louis was never meant to get the title of prince at all and the only reason this massive change was made to the royal family rules is all because of his great-grandmother, Queen Elizabeth.
Back in 1917, George V decided that the royal titles should be limited. He had stated that only the monarch, their children, grandchildren and the Prince of Wales's first grandson could have the official status. If the royal family were to follow these rules, only Prince George would have been entitled to the status of a prince while the rest of his siblings would not have received it.
In this case, Princess Charlotte would have been known as Lady Charlotte Mountbatten-Windsor and new baby Louis would have been Lord Louis Mountbatten-Windsor. Similar, If Kate and William had given birth to a daughter instead of Prince George, she would have been known to be a princess while the rest of the siblings would have been given a different title.
However, Queen Elizabeth is not someone who waits for others to tell her what to do but rather acts on her instincts and what she thinks is right.
She changed the royal rules even before Prince George was born in order to ensure that his great-grandchildren were given the title. Just before George was born, the Queen issued a Letters Patent, which is a legal procedure which enables her to make a change without it going through Parliament, and made the desired changes.
The notice which was published stated, "The Queen has been pleased by Letters Patent under the Great Seal of the Realm dated 31 December 2012 to declare that all the children of the eldest son of the Prince of Wales should have and enjoy the style, title and attribute of royal highness with the titular dignity of Prince or Princess prefixed to their Christian names or with such other titles of honour."
The announcement was later made in 2013 during Kate's 31st birthday. This was also the time when she was pregnant with Prince George. This new rule meant that all Prince William and Kate's children will have the royal title of a prince or a princess.