From the archives of NPR:
If you were standing outside the Louvre in Paris on the morning of Aug. 21, 1911, you might have noticed three men hurrying out of the museum.
They would have been pretty conspicuous on a quiet Monday morning, writer and historian James Zug tells weekends on All Things Considered host Guy Raz. “Sunday night was a big social night in Paris,” he says, “so a lot of people were hung over on Monday morning.”
The men, three Italian handymen, were not hungover. But they might have been a little tired. They'd just spent the night in an art-supply closet.
And on that morning, with the Louvre still closed, they slipped out of the closet and lifted 200 pounds of painting, frame and protective glass case off the wall. Stripped of its frame and case, the wooden canvas was covered with a blanket and hustled off to the Quai d'Orsay station, where the trio boarded a 7:47 a.m. express train out of the city.
They'd stolen the “Mona Lisa.”
Before its theft, the “Mona Lisa” was not widely known outside the art world. Leonardo da Vinci painted it in 1507, but it wasn't until the 1860s that critics began to hail it as a masterwork of Renaissance painting. And that judgment didn't filter outside a thin slice of French intelligentsia.
“The 'Mona Lisa' wasn't even the most famous painting in its gallery, let alone in the Louvre,” Zug says.