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
Also, according to Henry F. Pulitzer in his book "Where is the Mona Lisa?" (1960), Gian Paolo Lomazzo, an artist and writer, refers in his "Trattato dell'arte della Pittura Scultura ed Architettura" (1584), to ""della Gioconda, e di Mona Lisa" (the Gioconda, and the Mona Lisa)". "La Gioconda" is sometimes used as an alternative title of the "Mona Lisa" hanging in the Louvre; the reference implies that these were, in fact, two separate paintings. Pulitzer reproduces the critical page from Lomazzo's tract in his own book.