Charlotte’s great aunt Princess Anne, who is celebrating her 68th birthday today, was given the title by her mother, Queen Elizabeth, in 1987 when she was 36 years old — but it wasn’t automatically inherited as much as awarded. (In other words, it’s not a guarantee.) Only one living woman can be called the Princess Royal, which is why the Queen never had the title herself: Her aunt, Princess Mary, possessed the title until her death in 1965.
Since Prince Charles has no daughters, the next potential Princess Royal is 3-year-old Princess Charlotte. That, of course, is a long way off, and dependent on two factors: Prince William would need to be king, and Princess Anne would need to no longer be alive for Charlotte to be named Princess Royal.
However, the Succession to the Crown Act 2013 may change everything. The act stated that birth order determines who will become the next king or queen of the U.K., regardless of gender. Had it not been in place, Charlotte would have lost her spot when mum Kate Middleton gave birth in April to her younger brother, Prince Louis.
Since Princess Royal has a lower status than a royal dukedom, it’s possible that Charlotte will be given a peerage when she gets married, making her a duchess. After all, it’s likely that both of her brothers will be made dukes.
Ultimately, it will be a decision made by Prince William when he becomes monarch.
There have only been seven women with the title of Princess Royal since its introduction, when Queen Henrietta Maria, daughter of Henry IV, King of France, and wife of King Charles I wanted to imitate the way the eldest daughter of the King of France was styled “Madame Royale.” Her daughter, Mary, was the first to hold the title from 1642 to 1660.
And Kate and William’s daughter wouldn’t be the first with her name to hold the title! Charlotte, Princess Royal, was the daughter of King George III and used the title from 1789 to 1828.
This article originally appeared on PEOPLE