Leonardo returns in June 1506 to Milan in June 1506, called here to work for the new French government.

The small portrait known as the Mona Lisa or "la Gioconda", the laughing one, is arguably the most famous painting in the world today.

Its fame rests, in particular, on the elusive smile on the woman's face, its mysterious quality brought about perhaps by the fact that the artist has subtly shadowed the corners of the mouth and eyes so that the exact nature of the smile cannot be determined.

The shadowy quality for which the work is renowned came to be called sfumato or Leonardo's smoke.

Other characteristics found in this work are the unadorned dress, in which the eyes and hands have no competition from other details, the dramatic landscape background in which the world seems to be in a state of flux, the subdued coloring and the extremely smooth nature of the painterly technique, employing oils, but laid on much like tempera and blended on the surface so that the brushstrokes are indistinguishable.