Queen Elizabeth is currently the longest-reigning monarch in British history, but the day will come at some point where she will no longer rule, whether she sits on the throne until her dying day or chooses to step down in two years as recent rumors suggest. Whenever that day comes, however, several members of her family are set to receive some new titles—including a surprising one for her granddaughter-in-law, Kate Middleton.

According to Express UK, the various titles members of the royal family hold will change upon the end of Queen Elizabeth’s reign. Should she choose to step down on her own, her husband, Prince Philip becomes Guardian of the Queen, while her son, Prince Charles, becomes the King of England and his wife, Camilla, Duchess of Cornwall, becomes the Queen Consort. However, the titles that will be bestowed upon Charles’ heir, Prince William, his wife and their three children are some of the more surprising ones.

For now, Prince William and Kate are known as the Duke and Duchess of Cambridge, while their children’s official titles are Prince George of Cambridge, Princess Charlotte of Cambridge and Prince Louis of Cambridge. When they eventually all move up in the line of succession, Prince William will obtain the title vacated by his father and become the new Prince of Wales.

By proxy, Middleton will earn the title of Princess of Wales—which was last held by her late mother-in-law, Princess Diana. Though Camilla Parker Bowles is Prince Charles’ current wife, she abstained from taking the title after their marriage out of respect for Diana, who passed away eight years prior. However, when William assumes his new title, Kate is expected to accept it in Diana’s honor.

Of course, Middleton has proven to be popular with members of the public over the years and taking the title likely won’t cause too much controversy. However, there will likely be some pressure that comes with the title, due to Princess Diana’s popularity and reputation as “The People’s Princess.”

Queen Elizabeth, Kate Middleton Queen Elizabeth II and Catherine, Duchess of Cambridge visit King's College to officially open Bush House, the latest education and learning facilities on the Strand Campus on March 19, 2019 in London, England. Photo: Getty Images/Paul Grover