In case of an invasion, the valuable gems now property of Queen Elizabeth II were put inside no other than a biscuit tin, a royal BBC documentary called The Coronation will reveal on Sunday night.
This biscuit tin was stored inside a secure hiding place within the grounds of Windsor Castle, where young Elizabeth stayed during the war.
So how was the hiding place for the Crown Jewels constructed?
King George VI, Elizabeth II’s father, ordered a hole to be dug in the earth at the castle.
Inside the hole, two chambers were built with steel doors, and the biscuit tin containing the Crown Jewels was stored there.
The Crown Jewels are said to be worth several billion pounds, with one particular gem worth £400 million alone.
The secret will be revealed by Alastair Bruce, a royal commentator who presented the documentary.
“What was so lovely was that the Queen had no knowledge of it,” Alastair told The Times.
“Telling her seemed strangely odd,” he added of the big revelation.
Alastair will reveal the hiding place was revealed in a “set of letters” from Sir Own Morshead, the royal librarian, to Queen Mary, George VI’s mother.
The Queen’s official bra fitter was dropped recently after owner June Kenton published a tell all book.
June, former owner of Kensington bra fitters Rigby & Peller, published details of the Queen’s bra fitting.
As a consequence the lingerie company has been forbidden to display the royal coat of arms and has been stripped of its royal warrant.
The bra-fitter described carrying out bra-fittings with the Queen, stating that royal was half-dressed and her famous corgis were present at the time.