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.
Lisa del Giocondo
Centuries after Lisa's death, the "Mona Lisa" became the world's most famous painting and took on a life separate from Lisa, the woman. Speculation by scholars and hobbyists made the work of art a globally recognized icon and an object of commercialization. In 2005, Lisa was definitively identified as the model for the "Mona Lisa".