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.
Isleworth Mona Lisa
The "Isleworth Mona Lisa" is wider than the "Mona Lisa" in the Louvre, having columns on either side which also appear in some other versions. The Louvre painting merely has the projecting bases of columns on either side, suggesting that the picture was originally framed by columns but was trimmed. However, experts who examined the "Mona Lisa" in 2004–2005 stated that the original painting had not been trimmed.