Mona Lisa
Leonardo da Vinci is thought by some to have begun painting the "Mona Lisa" in 1503 or 1504 in Florence, Italy. Although the Louvre states that it was "doubtless painted between 1503 and 1506", the art historian Martin Kemp says there are some difficulties in confirming the actual dates with certainty. In addition, many Leonardo experts, such as Carlo Pedretti and Alessandro Vezzosi, are of the opinion that the painting is characteristic of Leonardo's style in the final years of his life, post-1513. Other academics argue that, given the historical documentation, Leonardo would have painted the work from 1513. According to Leonardo's contemporary, Giorgio Vasari, "after he had lingered over it four years, [he] left it unfinished". Leonardo, later in his life, is said to have regretted "never having completed a single work".
Circa 1504, Raphael executed a pen and ink sketch, today in the Louvre museum, in which the subject is flanked by large columns. Experts universally agree it is based on Leonardo's portrait of "Mona Lisa". Other later copies of the "Mona Lisa", such as those in the National Museum of Art, Architecture and Design in Oslo and The Walters Art Museum in Baltimore, also display large flanking columns. As a result, it was originally thought that the "Mona Lisa" in the Louvre had side columns and had been cut. However, as early as 1993, Zöllner observed that the painting surface had never been trimmed. This was confirmed through a series of tests conducted in 2004. In view of this, Vincent Delieuvin, curator of 16th-century Italian painting at the Louvre museum states that the sketch and these other copies must have been inspired by another version, while Frank Zöllner states that the sketch brings up the possibility that Leonardo executed another work on the subject of Mona Lisa.
Vincenzo Peruggia
In 1911, Peruggia perpetrated what has been described as the greatest art theft of the 20th century. It was a police theory that the former Louvre worker hid inside the museum on Sunday, August 20, knowing the museum would be closed the following day. But, according to Peruggia's interrogation in Florence after his arrest, he entered the museum on Monday, August 21 around 7 am, 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 , and the "Mona Lisa" measures approx. , 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.