The Queen, then Princess Elizabeth, spent her early childhood years at her parents' home 145 Piccadilly in London, which is now the site for InterContinental London Park Lane.
But what did it look like when the monarch lived there? Princess Elizabeth and her sister Princess Margaret stayed in the impressive five-storey townhouse overlooking Green Park with their parents the Duke and Duchess of York until 1936 – shortly before it was destroyed in World War Two.
A few unearthed photos have shared a peek at the property, while a detailed account of the interiors by Jane Dismore, author of Princess: The Early Life of Queen Elizabeth II, has given a better idea of the incredible family home.
WATCH: Inside the royal homes of the Queen, Princess Anne & more
The hallway reportedly featured pale green columns and soft brown carpet that led to the morning room, which Jane said "did not embrace the fashionable designs of the 1920s." It featured chintz-covered armchairs and a Persian carpet, while windows looked onto the garden.
Inside, there was a huge gramophone, lots of books, family photographs and a large glass cabinet containing minute animals for the Princesses to play with.
Princess Elizabeth and her mother in the garden of 145 Piccadilly
Her Majesty was pictured with her pet corgis Jane and Dookie in the family's garden, which featured a wooden bench, a large lawn surrounded by trees and a small wooden structure.
The young Princesses playing in their garden
The ground floor was also home to her father’s study and a dining room that could accommodate thirty guests, while the first floor housed her mother’s bedroom and boudoir. Elsewhere in the home was a ballroom, a library and twenty-four more bedrooms.
Elizabeth and Margaret had their own night and day nurseries on the top floor, decorated with red carpets, fireplaces and armchairs.
The sisters posed next to Margaret's cot at an exhibition of royal treasures in 1939
According to Jane, the day nursery also featured a tall dresser with glass cupboards that were "filled with toys and curios from all over the British Empire...many of them gifts from Queen Mary."
The family's home was bombed during World War Two
The family split their time between 145 Piccadilly and their country home Royal Lodge, Windsor, which is now home to Prince Edward and Sarah Ferguson. After Princess Elizabeth's father King George VI took the throne in 1936, they took up residence at Buckingham Palace and 145 Piccadilly was put on the market for rental.
Luckily, the royals were not at the property in December 1940 when the home was badly damaged by World War Two bombs.
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.