Leonardo's Mona Lisa

Leonardo began this portrait in 1503, and there is evidence he was still adjusting it fourteen years later. The sitter is widely believed to be Lisa Gherardini, wife of a Florentine silk merchant named Francesco del Giocondo, though Leonardo himself left no written confirmation and never delivered the painting to the family who commissioned it. He carried it with him when he moved to France in 1516, and it remained in his possession until his death in 1519. King Francis I acquired it afterward, and it entered the French royal collection.

The technique is sfumato, a method Leonardo refined over decades. He applied oil paint in glazes thin enough to be translucent, building up tone and colour through accumulated layers rather than through single opaque strokes. The result is that no individual brushstroke is visible on the surface. Light penetrates the glaze layers, reflects off the white poplar panel beneath, and returns through them, creating a softness that has no hard edges. The shadows around the eyes, the temples, the sides of the nose, and especially the corners of the mouth are not painted as lines but as gradients that the eye cannot fix into a boundary.

The landscape behind the figure is not a real place. It is an invented terrain of rocky outcrops, winding paths, a bridge, and distant water, rendered in blues and greens that fade into atmospheric haze. But the two sides do not match. The horizon line on the left is lower than the one on the right, so that the landscape appears tilted or split. Whether Leonardo intended this, or whether the panel warped after he painted it, remains unresolved. The effect, intended or not, is that the figure is solid and frontal while the world she sits against is unstable.

The painting hung in the Louvre for more than a century without exceptional fame. It was admired by those who studied Leonardo, but it was not mobbed, and it was not widely reproduced. That changed in 1911. On 21 August, an Italian handyman named Vincenzo Peruggia removed the painting from the wall during the museum's closed day, hid it under his coat, and walked out. The theft was not discovered until the following day. The empty space on the wall became news across Europe and then across the world.

Peruggia kept the painting in his Paris lodgings for two years, then took it to Florence and attempted to sell it to the Uffizi Gallery. He was arrested in December 1913. He claimed he had stolen it out of patriotism, believing it should be returned to Italy. The trial was brief; he served seven months. The painting was exhibited in Florence, Rome and Milan before being returned to France in January 1914. By then, its fame had become structural. The theft had converted a painting into a news event, and the news event had made it the most recognised artwork in the world.

Since its return, the Mona Lisa has hung in the Louvre behind glass, and since 2005 behind climate-controlled bulletproof glass in the Salle des États. It has been lent out for exhibition only a handful of times. It has been valued, insured, sung about, parodied, and visited by millions annually. The painting that Leonardo never finished and never gave up has become the single image most people name when asked to name a painting.