Why is the Mona Lisa famous? Skill, mystery and a theft

Why is the Mona Lisa famous? Because of four things that happened in order. Leonardo da Vinci painted a portrait more lifelike than any before it; it passed into the French royal collection and then the Louvre; 19th-century writers turned its smile into a mystery; and in 1911 it was stolen, which put it on front pages around the world for more than two years. After that, copies, parodies and queues kept it the most famous painting there is.

In short

• The painting is a small portrait, 79.4 by 53.4 cm, in oil on a poplar panel, begun around 1503 and probably of Lisa Gherardini, a Florentine merchant's wife.
• Leonardo's soft, smoky shading, called sfumato, makes her face and smile seem to change as you look, which is a real effect of how eyes see.
• Until 1911 it was admired by experts but no household name; the theft is what made it a celebrity.

What is the Mona Lisa, plainly?

The Mona Lisa is a half-length portrait of a seated woman, her hands folded, in front of a hazy, imaginary landscape of winding roads, a bridge and water. The Louvre's own catalogue entry gives the facts that most people get wrong: it is 79.4 cm tall and 53.4 cm wide, smaller than many visitors expect; it is painted in oil on a panel of poplar wood, not canvas; and it is dated 1503 to 1519, because Leonardo kept working on it for years and never delivered it.

The sitter is, by a tradition dating to the 16th century, Lisa Gherardini (1479–1542), who in 1495 married Francesco del Giocondo, a silk merchant of Florence. That is where both of its names come from: "Mona" is short for madonna, "my lady", and in Italian and French it is La Gioconda or La Joconde, after her married name, which also means "the cheerful one". In 2005 a scholar at Heidelberg University found a note written in the margin of a book in October 1503 by Agostino Vespucci, a Florentine official, saying Leonardo was then working on a portrait of Lisa del Giocondo. Most art historians take the identification as settled; the Louvre calls the rival theories a "false problem", though a few still propose other sitters.

What made the painting remarkable in its own day?

Its technique. Leonardo built the face from many thin, translucent layers of glaze, with no hard outlines, so that shadows melt into light. The Italians called the effect sfumato, "smoky". Around the corners of her mouth and eyes, where an expression is read, everything is blurred, and so the expression is open: it can look like a smile, or not.

There is a reason for that beyond art. In 2000 the Harvard neuroscientist Margaret Livingstone showed that the smile is clearer in peripheral vision, which picks up blurry, low-detail shadows, than in direct vision, which sees fine detail. Look at her eyes and she smiles; look at her mouth and the smile fades. Leonardo, who studied optics and anatomy, may not have known the science, but he painted the effect.

Other choices were new too. She turns toward the viewer in a three-quarter view, a pose that would become standard for portraits; the landscape behind her doesn't match on the left and right, which makes her seem to rise out of it. The artist and biographer Giorgio Vasari, writing in 1550, praised it as proof of "how closely art could imitate nature", though Vasari may never have seen it: he admired its eyebrows, which the painting today doesn't visibly have.

How did it become the most famous painting in the world?

Not quickly. For most of its life it was one admired painting among many. This timeline shows how fame built up, and the moment it jumped.

When	What happened	What it did for its fame
About 1503–1519	Leonardo paints it in Florence and keeps reworking it in Milan, Rome and France	Never delivered, so it stays with the artist
1518	King Francis I of France, Leonardo's last patron, very probably buys it	It enters the royal collection, at Fontainebleau and later Versailles
1797	After the French Revolution it goes on display at the Louvre, now a public museum	Anyone can see it; Napoleon briefly hangs it in his bedroom
1850s–1860s	French writers such as Théophile Gautier, then the English critic Walter Pater, describe her as mysterious and dangerous	The smile becomes a riddle; Leonardo becomes the model of a genius
21 August 1911	Vincenzo Peruggia, an Italian who had worked at the Louvre, walks out with it	Newspapers worldwide print its face for two years; crowds come to stare at the empty wall
December 1913	Peruggia tries to sell it to the Uffizi Gallery in Florence and is arrested	It tours Italy before returning to Paris on 4 January 1914, more famous than ever
1919	Marcel Duchamp draws a mustache on a postcard of it, L.H.O.O.Q.	It becomes the image artists parody to mock high art
1962–1963	Lent to the United States, shown in Washington and New York; more than a million people queue to see it	The first blockbuster art tour; Andy Warhol makes prints of it
1974	Shown in Tokyo and Moscow	Its fame becomes global
2005	Moved to its own glass case in the Louvre's largest room	A destination in itself

The theft is the turning point. Before 1911 the Mona Lisa was known mainly to experts and travelers with guidebooks. Peruggia, who had helped build the museum's glass cases, got into the Louvre on a Monday, when it was closed to the public, took the panel off the wall and left with it under a smock. The police questioned the poet Guillaume Apollinaire and even a young Pablo Picasso, both later cleared. Peruggia kept it in his Paris room for over two years and said he wanted to return it to Italy. He served a short prison sentence and was treated by many Italians as a patriot.

Is it famous because it's the best painting ever made?

Not on its own. Many art historians rank it among the great portraits, but quality alone doesn't explain why it draws more visitors than Leonardo's other works, or than the Louvre's other masterpieces. Its fame is partly a feedback loop: it is famous because it is famous. Each parody, ad, film and selfie adds to the stock of images, and a painting everyone knows becomes the one everyone has to see. The former Louvre director Henri Loyrette reckoned that 80 percent of the museum's visitors only wanted to see the Mona Lisa.

That loop has a cost. The painting was put behind glass after a man cut it with a razor blade; on 30 December 1956 a rock thrown by a visitor broke that glass and chipped the paint near her left elbow, and since then the glass has been bulletproof, and every attack since, red paint in Tokyo in 1974, a teacup in 2009, a cake in 2022 and soup thrown by environmental protesters in January 2024, has hit the glass and not the painting. Most visitors now see it from several meters away, behind a crowd, for a minute or two.

What about the secret codes and the golden ratio?

There is no good evidence for them. Claims that Leonardo laid out the face on the golden ratio don't survive measurement, and he left no notes saying he used it. Hidden letters in the eyes and secret messages belong to novels and documentaries, not scholarship. What scientific study has found is more interesting: X-ray and infrared images made by France's museum research laboratory show layer on layer of changes, the traces of an artist working slowly on one panel for years.

Still argued

A few questions are genuinely open. Why Leonardo never delivered the portrait to Francesco del Giocondo is unknown; he may have kept it as a showpiece of his method. Who commissioned the later stages is unclear: a visitor's secretary in 1517 recorded a Florentine lady painted for Giuliano de' Medici, and scholars disagree whether that was a slip or a clue to a second commission. And a rival "Isleworth Mona Lisa", promoted since 2012 as an earlier version by Leonardo, is rejected by most specialists.

The Mona Lisa is the clearest case of how a work becomes famous through what happens to it as much as what is in it. To see how its world produced it, start with the Renaissance; for why a painting is art at all, what art is; and for a painter who sold almost nothing in his life and became nearly as famous, Vincent van Gogh.

Check yourself

• Without looking back: name the four stages that made the Mona Lisa famous, in order.
• Why does her smile seem to appear and disappear, according to Livingstone's research?
• What did the 1911 theft change, and why would a theft make a painting more famous rather than less?

Sources

• Portrait of Lisa Gherardini, wife of Francesco del Giocondo, known as the Mona Lisa — Musée du Louvre, collections database
• From the Mona Lisa to The Wedding Feast at Cana: the Salle des États — Musée du Louvre
• Lives of the Most Eminent Painters, Sculptors and Architects, Vol. 4 — Giorgio Vasari, 1550, translated by Gaston du C. de Vere, Project Gutenberg
• Mona Lisa — Wikipedia