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
The title of the painting, which is known in English as "Mona Lisa", comes from a description by Renaissance art historian Giorgio Vasari, who wrote "Leonardo undertook to paint, for Francesco del Giocondo, the portrait of Mona Lisa, his wife." "Mona" in Italian is a polite form of address originating as "ma donna" – similar to "Ma’am", "Madam", or "my lady" in English. This became "madonna", and its contraction "mona". The title of the painting, though traditionally spelled "Mona" (as used by Vasari), is also commonly spelled in modern Italian as "Monna Lisa" ("" being a vulgarity in some Italian dialects), but this is rare in English.