The secret the royal family have chosen to keep from Prince George.

The Duke and Duchess of Cambridge’s three children – Prince George, Princess Charlotte and Prince Louis – are some of the most famous in the world, and it’s understandable that their family would want to protect them from the inevitable public attention they receive from being royals.

One way Prince William and Kate Middleton are protecting their eldest son, reports The Mirror, is to withhold a crucial part of information from him. It’s believed Prince George doesn’t know about his potential future role in the royal family as third in line to the throne.

The couple want their children to live as normal a life as possible while they are growing up, and not feel the profound pressure that the knowledge of their future roles might bring, especially for their first born.

According to The Mirror, Prince William said in an interview, “There’ll be a time and a place to bring George up and understand how he fits in the world,” adding they are a “very normal” family.

In an interview with GQ Magazine in 2017, the Duke of Cambridge said, “I want George to grow up in a real, living environment, I don’t want him growing up behind palace walls”.

He added that whilst he can accept that growing up in the royal family is an abnormal life, he “can still try to protect them as children.”

Prince George celebrates his fifth birthday today, and the Duke and Duchess of Cambridge released a portrait to mark the special occasion.

The Duke and Duchess of Cambridge are very pleased to share a new photograph of Prince George to mark his fifth birthday – thank you everyone for your lovely messages ???? ???? @mattporteous

A post shared by Kensington Palace (@kensingtonroyal) on Jul 21, 2018 at 2:30pm PDT

Catherine Mayer, who wrote Charles: The Heart of a King, has explained that their decision to keep Prince George’s future a ‘secret’ for now, is partly due to the fact that Prince William struggled knowing he was in line to follow in the footsteps of his grandmother, Queen Elizabeth II, when he was growing up.

Mayer told E! News in 2015 that the Duke and Duchess of Cambridge are therefore wanting to “delay that moment of realisation and give him normality before they thrust this onto him.”

“But it will be, nevertheless, part of his upbringing both in terms of what he sees his parents and grandparents doing and probably quite soon a beginning of an understanding that he is in public life and what that means.”

With Prince George now at school, attending St Thomas’ of Battersea in London, it’s likely the secret of his future role will become harder and harder to keep.