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
During the Franco-Prussian War (1870–71) it was moved from the Louvre to the Brest Arsenal. During World War II, "Mona Lisa" was again removed from the Louvre and taken safely, first to Château d'Amboise, then to the Loc-Dieu Abbey and Château de Chambord, then finally to the Ingres Museum in Montauban.