The portrait of the Mona Lisa by Leonardo da Vinci was stolen in August 1911 by a worker, the painter-glass worker Vincenzo Peruggia. Employed for several years at the Louvre, he participated in the work of putting the Salon Carré under glass. He knew everyone at the museum and he knew the security operators. Since the museum was closed to the public on Mondays, he locked himself in one Sunday night. Dressed in a workman's coat, he took advantage of the absence of the staff in the room where the Mona Lisa was on display and simply took it down. At the turn of a staircase, he removed its frame and hid it under his coat. He calmly exited the Louvre with the painted wooden panel under his arm...