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.
Mona Lisa replicas and reinterpretations
It is a painting of the same subject as Leonardo da Vinci's "Mona Lisa". The painting is claimed by a majority of experts to be mostly an original work of Leonardo dating from the early 16th century: a survey of all published opinions shows that 22 experts are certain that the major parts of the "Isleworth Mona Lisa" are the work of Leonardo da Vinci.