It was in August 1911, when the event took place in the Louvre Museum, Paris. Back then the Mona Lisa certainly wasn’t universally known which is now known as the world’s most famous painting.

A hundred years ago on 21 August 1911 at 7 AM, a person named Vincenzo Peruggia entered in Louvre Museum through the door where the other Louvre workers were entering. He wore one of the white smocks that museum employees customarily wore and was indistinguishable from the other workers. He lifted the painting off the four iron pegs that secured it to the wall and took it to a nearby service staircase. There, he removed the protective case and frame. He took off his smock and wrapped it around the painting, tucked it under his arm, and left the Louvre through the same door he had entered. Peruggia hid the painting in his apartment in Paris.
It was 24 hours before anyone noticed the painting was missing. The usual line is that the Louvre was closed for maintenance and everyone thought that somebody else must have removed the picture to be photographed, or cleaned. But museums are – or were – surprisingly blind to crime, even when it involves stealing the world’s most famous painting.
After the knowledge of the disappearance of the painting, French police printed off 6,500 copies for distribution in the streets of Paris, as if to jog someone’s memory. Those mug-shots were also for comparison with any forgery that might turn up purporting to be the original.

One of the first suspects was Pablo Picasso. The painter had nothing to do with the crime but immediately tried to dispose of some statues that turned out to have been stolen from the same museum. The poet Guillaume Apollinaire was also brought in for questioning. No charges were brought, though suspicion followed Picasso for a while – surely a great painter would want a great painting, ran the theory. For almost two years the trail went cold.
After keeping the painting hidden in a trunk in his apartment for two years, Vincenzo Peruggia returned to Italy with it. He kept it in his apartment in Florence, Italy but grew impatient, and was finally caught when he contacted Alfredo Geri, who he hoped would help him dispose of this unsaleable hostage for cash. Alfredo Geri was the owner of an art gallery in Florence. Geri’s story conflicts with Peruggia’s, but it was clear that Peruggia expected a reward for returning the painting to what he regarded as its “homeland”.

A picture that could still come as something of a surprise: unthinkable now, but in those days reproductions of the Mona Lisa had only fairly recently become popular. What put a face to the name was the press coverage inspired by the theft. Every major newspaper in Europe covered the story, and every story was illustrated with a reproduction of the painting. One paper, France’s l’Illustration, even produced a centerspread, peddling the story that Leonardo had been in love with his sitter, and promising to work towards a colour reproduction within a couple of weeks. Millions of people who might not have seen it, might never even have heard of it, soon became experts on Leonardo’s stolen painting.
After its recovery, the painting was exhibited all over Italy with banner headlines rejoicing its return and then returned to the Louvre in 1913. While the painting was famous before the theft, the notoriety it received from the newspaper headlines and the large scale police investigation helped the artwork become one of the best known in the world.