The painting’s fame was emphasized when it was stolen on 21 August 1911. The next day, Louis Béroud, a painter, walked into the Louvre and went to the Salon Carré where the Mona Lisa had been on display for five years. However, where the Mona Lisa should have stood, he found four iron pegs. Béroud contacted the section head of the guards, who thought the painting was being photographed for marketing purposes. A few hours later, Béroud checked back with the section head of the museum, and it was confirmed that the Mona Lisa was not with the photographers. The Louvre was closed for an entire week to aid in investigation of the theft.
French poet Guillaume Apollinaire, who had once called for the Louvre to be “burnt down,” came under suspicion; he was arrested and put in jail. Apollinaire tried to implicate his friend Pablo Picasso, who was also brought in for questioning, but both were later exonerated.