Royal Couples
Prince Harry has a unique nickname for Kate Middleton. Pictured: Royal couples watch the RAF flypast on the balcony of Buckingham Palace, as members of the Royal Family attend events to mark the centenary of the RAF on July 10, 2018 in London, England. Getty Images/Chris Jackson

Prince Harry and Kate Middleton have a close relationship to each other, and he calls her by a special nickname.

While Prince William calls his wife darling or poppet, and Middleton calls him babe, Prince Harry calls his sister-in-law Cath. The nickname is derived from Middleton’s real name, Catherine.

During an interview with radio presenter Scott Mills, Middleton said, “I’m not sure, I’m not that familiar with it. But I will answer to most things.”

Last month, Isabella Sullivan, a journalist for Express, claimed that the members of the royal family call each other by their nicknames when they are at home. Prince Charles, Prince William, and Prince Harry reportedly call Queen Elizabeth II Mama. Prince George and Princess Charlotte call the Queen Gan-Gan.

When Prince William was still very young, he couldn’t pronounce grandma so he ended up calling Her Majesty “Gary Gary.”

Prince Charles reportedly calls Meghan Markle Tungsten, while former actress, calls her husband, Prince Harry, Haz.

In 2007, Prince William revealed during an interview that his mom, Princess Diana, used to call him Wombat. While speaking with Matt Lauer, he said, “It began when I was two. I’ve been rightfully told because I can’t remember back that far.”

“But when we went to Australia with our parents, and the wombat, you know, that’s the local animal. So I just basically got called that. Not because I look like a wombat, or maybe I do,” he added.

These days, Prince William is only referred to as Wills by his closest friends and relatives. But when he was still in school, he went by the name Steve to protect his identity while in the university. Prince Harry is also rumored to have used the fake name Henry for his Facebook account.

Middleton used to be called Squeak when she was still young. The moniker was inspired by her guinea pig who had the same name. During her visit to St. Andrew’s School in Berkshire, she said, “I was nicknamed Squeak just like my guinea pig. There was one called Pip and one called Squeak because my sister was called Pippa and I was Squeak.”