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.
Vandalism of art
"Mona Lisa" by Leonardo da Vinci has long been attracting vandals and is currently one of the best-protected artworks. In 1956, the lower part of the painting was severely damaged when a vandal doused the painting with acid while it was on display at a museum in Montauban, France. On 30 December of the same year, a young Bolivian named Ugo Ungaza Villegas threw a rock at the painting; this resulted in the loss of a speck of pigment near the left elbow, which was later painted over.