Isleworth Mona Lisa

The Isleworth Mona Lisa is a controversial painting depicting the same subject as the Louvre's Mona Lisa but in an apparently younger state, set against a background with columns. Proponents argue it is an earlier version by Leonardo from around 1503, while most mainstream scholars consider it a later copy by another hand. The painting was discovered in an English manor house in 1913 by art dealer Hugh Blaker, who acquired it from a Somerset family. It is currently held by the Mona Lisa Foundation in Switzerland, which has promoted the theory of Leonardo's authorship through extensive scientific analysis.

The painting shows a younger-looking woman than the Louvre version, with visible architectural columns framing the figure that correspond to the cut edges of the Louvre panel. The sfumato technique is less refined than Leonardo's authenticated works, with harder edges and less subtle tonal transitions, which critics cite as evidence against Leonardo's authorship.