Her smile is world famous. But who is the woman who modelled Leonardo da Vinci over 500 years ago? The best-known theory goes back to the biographer Giorgio Vasari. According to his records, da Vinci portrayed a woman named Lisa del Giocondo, wife of the cloth and silk merchant Francesco del Giocondo, during his stay in Florence (1500 to 1506). Giocondo had commissioned the portrait, but never received the finished oil painting. However, there is no proof of this theory. One thing is certain, there is hardly any other picture that has so many secrets. While some believe they see a man behind the enigmatic smile, others suspect that the woman without eyebrows is simply the imagination of the Renaissance painter. On the other hand, the assumption that the German title “Mona Lisa” is based on a spelling error is all the more likely. Because the Italian term “Monna”, short form of the word “Madonna”, means “woman”. So it is quite possible that it is not a first name, but just the title with which Lisa was addressed as a wife at the time. The original painting has been in the Musée du Louvre in Paris since the late 18th century. But whoever can be seen on it will remain Leonardo da Vinci’s secret.