Isleworth Mona Lisa
According to Leonardo's early biographer Giorgio Vasari, Leonardo had started to paint "Mona Lisa" in 1503, but "left it unfinished". However, a fully finished painting of a "certain Florentine lady" surfaced again in 1517, shortly before Leonardo's death and in his private possession. The latter painting almost certainly is the one that now hangs in the Louvre. Based on this contradiction, supporters of the authenticity of the "Isleworth Mona Lisa" claim it is the unfinished "Mona Lisa", made at least partially by Leonardo, and the Louvre "Mona Lisa" a later version of it, made by Leonardo for his own use.
Portrait
One of the best-known portraits in the Western world is Leonardo da Vinci's painting titled "Mona Lisa", which is a painting of Lisa del Giocondo. What has been claimed as the world's oldest known portrait was found in 2006 in the Vilhonneur grotto near Angoulême and is thought to be 27,000 years old.