"During World War II, the British royal family’s most precious gems were buried underground at Windsor Castle to protect them from discovery by the Nazis, a new documentary reveals. With Britain under air attack from the mighty German Luftwaffe, King George VI ordered palace staff to remove the most valuable of the Crown Jewels from the Tower of London and hide them in case of an invasion. They were stashed in an innocuous tin box that had previously contained biscuits. According to the Times (U.K.), the removal and hiding of the jewels has long been rumored. The most likely hiding place was believed to be Windsor Castle, the royal residence in England’s Berkshire county, though others suggested the gems might have been spirited out of the country to Canada and kept in a vault, hidden in a cave in Wales or in a secret tunnel under a Devonshire prison. But the details of the operation were kept so secret, it turns out, that not even Queen Elizabeth II—at the time a teenage princess—knew the whereabouts of the priceless gems. She learned the juicy details during the filming of an upcoming BBC documentary, when royal commentator Alistair Bruce spoke to her about a set of letters recently unearthed by Oliver Urquhart Irvine, the royal librarian and assistant keeper of the queen’s archives. In the letters, Sir Owen Morshead, then the royal librarian, described to Queen Mary (mother of King George VI) how he had removed the most precious jewels from the Imperial State Crown, the royal headgear worn by the sovereign while addressing the state opening of Parliament. Made for George VI’s coronation in 1937, the impressive crown is set with 2,868 diamonds and various colored stones, including 17 sapphires, 11 emeralds and 269 pearls, according to the Royal Collection Trust. Morshead pried the Black Prince’s Ruby (believed to have been given to Edward, Prince of Wales, by a Spanish king in 1367 and later worn by Henry V in his helmet during the Battle of Agincourt) and the St. Edward’s Sapphire (which goes back to Edward the Confessor, an 11th-century Anglo-Saxon king) from their clasps, and hid them in a tin box previously containing Bath Oliver biscuits. The hard, dry crackers, still popular among Britons, were created by a Regency-era physician to help patients suffering from gout and obesity. Palace staff then dug a deep hole beneath one of the secure entrances to Windsor Castle, covering the excavations at night to avoid detection by the Luftwaffe. When Nazi aircraft flew over at night,“they had to hide it with tarpaulins,” Bruce tells the Times. Inside a specially constructed chamber with steel doors, they locked the biscuit tin containing the jewels. The chamber was accessible by a trapdoor, which still exists today. Far beyond keeping the Crown Jewels safe, it was lucky for Britain—and the world—that King George VI was on the throne during World War II rather than his brother, the former King Edward VIII, who had abdicated in 1936 over the crisis surrounding his marriage to American divorcée Wallis Simpson. As viewers of the hit Netflix series The Crown will remember, the Duke and Duchess of Windsor were highly sympathetic to the Nazis, visiting Hitler at his vacation retreat in Berchtesgaden in 1937 and even participating in a Nazi plan to reinstall him on the throne in his brother’s place. Edward’s pro-Nazi past emerged through the post-war discovery of German diplomatic papers known as the Marburg Files. King George VI died unexpectedly in 1952, elevating his 27-year-old daughter to the throne." Source: https://www.history.com/news/british-royals-hid-crown-jewels-from-nazis-in-a-cracker-box