Return of the Mona Lisa at the end of World War Two. --- On the eve of war, curators at the Louvre swathed the museum's most priceless painting in layers of waterproof paper, boxed it up and spirited it to the French countryside for safekeeping. The painting was moved another five times during the war before she was safely returned to the Louvre after the Liberation.
Enigma Machine - Enigma Machine During World War II, the Germans used the Enigma, a cipher machine, to develop nearly unbreakable codes for sending messages. The Enigma's settings offered 150,000,000,000,000,000,000 possible solutions, yet the Allies were eventually able to crack its code. By end of the war, 10 percent of all German Enigma communications were decoded at Bletchley Park, in England, on the world’s first electromagnetic computers.
Josephine Baker in her World War II Uniform, c. 1945. During World War II, she worked with the French resistance movement. Using her career as a cover, Baker carried secret messages written in invisible ink on her sheet music.