Prince George, Princess Charlotte, and Prince Louis' strange nickname for Queen Camilla

When the royals are within the comfort of their home, official titles are set aside.

Each family member often has a special nickname, and Meghan Markle has even followed suit, affectionately calling her husband Prince Harry 'Haz' or 'H'.

The late Queen was known intimately as Lilibet among family while Prince William charmingly dubbed her 'Gary' during his younger years due to difficulties pronouncing 'grandma'.

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The youngest royal brood including Prince George, Princess Charlotte, and Prince Louis too have their endearing names for the elders. They're privy to tales of 'Granny Diana' and adorably call King Charles 'Grandpa Wales'.

The Daily Mail reports that this mirrors the name the young Queen Elizabeth gave her grandfather George V — 'Grandad England'.

Yet, when referring to Queen Camilla, it seems the norm of 'grandma' or 'nanny' isn't used. Camilla, a proud grandmother to five plus the Cambridge children and Archie and Lilibet, Meghan and Harry's little ones, is known simply as 'Gaga'.

During a warm exchange at the 2016 Royal Variety Performance, The Sun reports that Camilla informed Lady Gaga that her step-grandchildren affectionately called her 'GaGa'.

And after young Prince George's arrival, the Duchess told the Daily Mail: "My own grandchildren call me GaGa. I don't know if it's because they think I am! It is funny but is still very sweet."

Meanwhile, Prince George also had a charming pet name for his great-grandmother, the late Queen, affectionately referring to her as "Gan-Gan". Reflecting on family matters and the addition of Princess Charlotte in 2016, The Princess of Wales once shared: "It's very special having a new little girl...I feel very, very lucky that George has got a little sister.

"The Queen was really thrilled that it was a little girl, and I think as soon as we came back here to Kensington she was one of our first visitors here. 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."