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.
Speculations about Mona Lisa
The same claim has been made for a version in the Vernon collection. The Vernon "Mona Lisa" is particularly interesting because it was originally part of the collection at the Louvre. Another version, dating from c. 1616, was given in c. 1790 to Joshua Reynolds by the Duke of Leeds in exchange for a Reynolds self-portrait. Reynolds thought it to be the real painting and the French one a copy, which has now been disproved. It is, however, useful in that it was copied when the original's colors were far brighter than they are now, and so it gives some sense of the original's appearance 'as new'. It is in a private collection, but was exhibited in 2006 at the Dulwich Picture Gallery.