Leonardo worked on the Mona Lisa intermittently from 1503 until his death in 1519; the painting has almost no point at which it could be called definitively finished. It is generally accepted as a portrait of Lisa Gherardini, the wife of the Florentine merchant Francesco del Giocondo, though even this identification has occasionally been disputed.

The technical innovation is decisive. Leonardo dissolves facial features into what he called *sfumato* — soft transitions, almost atmospheric haze, especially around the eyes and lips. The expression therefore is not fixed; it appears to shift with the viewer's angle, and the famous 'enigmatic smile' is in part an optical effect of the technique. The mountain-and-river landscape behind her is among the most mature examples of aerial perspective (distant objects shifting toward blue) in European painting.

The panel has been in the Louvre collection since 1797. In 1911 it was stolen by an Italian museum worker and recovered two years later in Florence — the event transformed it from a known masterpiece into a global icon. Around ten million visitors a year now queue to see it in the Salle des États.

The Mona Lisa has become a symbol of what art can do beyond representation: interpret, evoke, and establish a reciprocal relationship with the viewer.