Vincenzo Peruggia an Italian museum worker, artist and thief, perpetrated what has been described as the greatest art theft of the 20th century, when he stole the Mona Lisa from the Louvre museum in Paris on  this day in 1911.

It was a police theory that the former Louvre worker hid inside the museum on August 20, a Sunday, knowing the museum would be closed the following day. But, according to Peruggia’s interrogation in Florence after his arrest, he had entered the museum on Monday, August 21, around 7:00 a.m., through the door where the other Louvre workers were entering. He said he wore one of the white smocks that museum employees customarily wore and was indistinguishable from the other workers.

When the Salon Carré, where the Mona Lisa hung, was empty, 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. Some people report that he concealed the painting (which Leonardo painted on wood) under his smock. But Peruggia was only 160 centimetres (63 in) tall, and the Mona Lisa measures approx. 53 cm × 77 cm (21 in × 30 in), so it would not fit under a smock worn by someone his size. Instead, he said 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.[4]

After keeping the painting hidden in a trunk in his apartment for two years, Peruggia returned to Italy with it. He kept it in his apartment in Florence, Italy for some time. However, Peruggia eventually grew impatient and was finally caught when he contacted Mario Fratelli, the owner of an art gallery in Florence. Fratelli’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”. Fratelli called in Giovanni Poggi, director of the Uffizi Gallery, who authenticated the painting. Poggi and Fratelli, after taking the painting for “safekeeping”, informed the police, who arrested Peruggia at his hotel. After its recovery, the painting was exhibited all over Italy with banner headlines rejoicing its return. The Mona Lisa was 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, gaining

-Wikipedia

-Photo Caption – The Mona Lisa on display in the Uffizi Gallery, in Florence (Italy). Museum director Giovanni Poggi (right) inspects the painting. The masterpiece would be latter returned to Museum of Louvre where it had been stolen from -Wikipedia