Portrait of Mona Lisa (1479-1528), also known as La Gioconda, the wife of Francesco del Giocondo; 1503-06 (150 Kb); Oil on wood, 77 x 53 cm (30 x 20 7/8 in); Musee du Louvre, Paris
This figure of a woman, dressed in the Florentine fashion of her day and seated in a visionary, mountainous landscape, is a remarkable instance of Leonardo's sfumato technique of soft, heavily shaded modeling. The Mona Lisa's enigmatic expression, which seems both alluring and aloof, has given the portrait universal fame.

What strikes us first is the amazing degree to which Lisa looks alive. She really seems to look at us and to have a mind of her own. Like a living being, she seems to change before our eyes and to look a little different every time we come back to her. Even in photographs of the picture we experience this strange effect, but in front of the original in the Louvre it is almost uncanny. Sometimes she seems to mock at us, and then again we seem to catch something like sadness in her smile.

The work should probably be dated during Leonardo's second Florentine period, that is between 1503 and 1505. Leonardo himself loved the portrait, so much so that he always carried it with him until eventually in France it was sold to François I, either by Leonardo or by Melzi.
From the beginning it was greatly admired and much copied, and it came to be considered the prototype of the Renaissance portrait. It became even more famous in 1911, when it was stolen from the Salon Carré in the Louvre, being rediscovered in a hotel in Florence two years later. It is difficult to discuss such a work briefly because of the complex stylistic motifs which are part of it. In the essay ``On the perfect beauty of a woman'', by the 16th-century writer Firenzuola, we learn that the slight opening of the lips at the corners of the mouth was considered in that period a sign of elegance. Thus Mona Lisa has that slight smile which enters into the gentle, delicate atmosphere pervading the whole painting. To achieve this effect, Leonardo uses the sfumato technique, a gradual dissolving of the forms themselves, continuous interaction between light and shade and an uncertain sense of the time of day.