She may have ruled Britain for 70 years, but to her great-grandchildren, she was known simply as "Gan-Gan".
Queen Elizabeth has died at the age of 96 at Balmoral, surrounded by her family.
She leaves behind eight grandchildren: Peter Phillips, Zara Tindall, Prince William, Prince Harry, Princess Beatrice, Princess Eugenie, Lady Louise Windsor, and James, Viscount Severn - and 12 great-grandchildren, including 9-year-old future king, Prince George.
Prince William, 40, spoke a lot about his relationship with the Queen during her reign, telling ABC News in a 2012 interview, "I learned from growing up, you don't mess with your grandmother."
His brother Harry told the outlet that "Behind closed doors, she's our grandmother, it's as simple as that."
Last year he paid tribute to the Queen during an interview with Oprah Winfrey, saying: "I've spoken more to my grandmother in the last year than I have done for many, many years. My grandmother and I have a really good relationship and an understanding... She's my colonel-in-chief, right? She always will be."
The Queen's 12 great-grandchildren are: Prince George, Princess Charlotte, Prince Louis, Archie Harrison Mountbatten-Windsor, Lilibet Diana Mountbatten-Windsor, Savannah Phillips, Isla Phillips, Mia Tindall, Lena Tindall, Lucas Tindall, August Philip Hawkes Brooksbank, and Sienna Elizabeth Mapelli Mozzi.
She met her youngest great-grandchild and her namesake Lilibet during her Platinum Jubilee, but denied Harry and Meghan's request to have a photographer present.
It was her first great-grandchild Prince George who came up with the nickname "Gan-Gan".
George has been photographed on several occasions alongside the Queen in official portraits. During the Platinum Jubilee, he was pictured speaking with his great-grandmother as they stood together on the balcony.
Princess Charlotte, whose middle names are Elizabeth and Diana in tribute to the Queen and to William's mum, shares a love of horses with the Queen.
William and Kate's third child Louis stole the limelight at the Queen's Jubilee, delighting the crowds as he chatted away to his grandmother at Trooping the Colour.
The Queen's granddaughter Zara has three children with husband Mike - Mia, Lena and Lucas Philip, named after the Queen's late husband.
The Queen was one of the first members of the royal family to meet Harry and Meghan's first child Archie when the couple brought him to Windsor Castle days after his birth. It's understood the Queen continued to video call the Sussexes after their move to the US, and would chat with Archie during the calls.
Princess Eugenie's son August Philip Hawkes Brooksbank was born in February 2021, and was christened with the Queen in attendance.
Lilibet Diana Mountbatten-Windsor was born in July 2021 in California, named in tribute to Elizabeth and to Harry's late mother. Sources claimed Harry asked the Queen for permission to use her deeply personal childhood nickname.
The Queen's youngest great-grandchild Sienna Mapelli Mozzi was born to Prince Andrew's oldest daughter Beatrice and her husband Edo. She has never been seen in public.
The new free open-air saltwater pool is already proving popular.