Like any other family, the royals have their own sweet and sometimes funny nicknames for one another. The Queen's moniker, Lilibet, was coined during her childhood when she struggled to pronounce her full name, Elizabeth, and it was even used by her late husband, the Duke of Edinburgh.
But did you know that Prince William had his own hilarious nickname for his grandmother when he was a child?
READ: 19 of the royal family's sweet and unusual nicknames revealed
WATCH: The sweet way Prince William says goodbye to the Queen
It's been widely reported that William, as a little boy, referred to the monarch as 'Gary'.
According to MailOnline's Richard Kay, the Queen was on hand after William fell over at Buckingham Palace, crying: "Gary, Gary." A guest is said to have asked who Gary was, to which Her Majesty replied: "I'm Gary. He hasn't learned to say Granny yet."
READ: Princess Charlotte has the most adorable nickname for dad Prince William
SEE: When royal history repeats itself - 15 striking photos you have to see
A two-year-old William at Prince Harry's christening in 1984
While the Queen's grandchildren refer to her as 'Granny', the youngest generation of royals also have their own sweet nicknames for the monarch.
The Duchess of Cambridge revealed Prince George's nickname for his great-grandmother in her first solo interview for the ITV documentary, Our Queen at Ninety, in 2016: "George is only two-and-a-half and he calls her 'Gan-Gan.' She always leaves a little gift or something in their room when we go and stay and that just shows her love for her family."
Prince William and Kate also have their own nicknames for their children, with one royal fan revealing in 2019 that the Duchess refers to her daughter as 'Lottie' instead of 'Charlotte'.
Kate's nickname at school was 'Squeak'
Kate herself was nicknamed 'Squeak' as a young girl at St Andrew's School in Berkshire. She explained how the name came about while on a visit to the school years later.
"I was nicknamed Squeak just like my guinea pig," she said. "There was one called Pip and one called Squeak because my sister was called Pippa and I was Squeak."
Popular at senior school, Kate was allegedly known as the "Princess-in-waiting" by her fellow Marlborough College pupils.
Make sure you never miss a ROYAL story! Sign up to our newsletter to get all of our celebrity, royal and lifestyle news delivered directly to your inbox.