Mona Lisa
The painting is thought to be a portrait of Lisa Gherardini, the wife of Francesco del Giocondo, and is in oil on a white Lombardy poplar panel. It had been believed to have been painted between 1503 and 1506; however, Leonardo may have continued working on it as late as 1517. Recent academic work suggests that it would not have been started before 1513. It was acquired by King Francis I of France and is now the property of the French Republic, on permanent display at the Louvre Museum in Paris since 1797.
Yves Chaudron
According to that account, in 1910, Valfierno had conspired with Chaudron to steal the "Mona Lisa" and produce copies of the painting which would then be sold to private buyers as the genuine painting. The plan had been to sell each copy as the "original" while the location of the real painting was unknown.