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
Joos van Cleve, a Flemish artist active in the years following "Mona Lisa"'s creation, also painted a nude titled "Mona Vanna". Though the figure portrayed in van Cleve's painting bears no resemblance to Leonardo's "Mona Lisa", the artist was known to mimic themes and techniques of Leonardo da Vinci, in this case the positioning of the figure and the delicate brushwork reminiscent of Leonardo's sfumato. The artwork, dating to the mid-16th century, is in the collection of the National Gallery, Prague.