Leonardo da Vinci began painting the Mona Lisa around 1503 and likely continued working on it until about 1517, meaning the portrait took shape over roughly 14 years. Most art historians date the start to 1503–1506, with later retouching extending into the 1510s. The painting today hangs at the Louvre in Paris. Those dates rest on documentary clues, not a single signed and dated inscription, which is why scholars still debate the exact start and finish.
The Documentary Evidence Behind the Dates
The strongest written clue comes from Giorgio Vasari, the 16th-century biographer who wrote that Leonardo started the portrait of Lisa Gherardini sometime around 1503. Vasari never saw the finished panel and may have conflated details, so historians treat his account as a starting point rather than proof. A second thread comes from Leonardo's own lifetime: an inventory and later references suggest he kept the painting with him, unfinished, for years.
The panel almost certainly traveled with Leonardo to France in 1516, when he entered the service of King Francis I. That move implies the portrait was still in his possession and possibly still being refined near the end of his life. A margin note from 1503 by Agostino Vespucci, a Florentine official, compares Leonardo to Apelles and mentions a portrait of Lisa del Giocondo in progress. That note anchors the early date more firmly than Vasari alone.
The absence of a firm completion date is the core problem. Leonardo rarely dated his work, and the Mona Lisa carries no inscription giving a year. The window of 1503 to about 1517 is a scholarly consensus built from overlapping clues, not a stamped record.
How a Single Poplar Panel Took Shape Over Years
The Mona Lisa is oil on a single poplar wood panel, roughly 30 by 21 inches (77 by 53 centimeters). Poplar was common in Florentine workshops because it was local and stable enough for small portraits. Leonardo prepared the surface with a ground layer, then built the image in many thin translucent oil glazes rather than thick opaque strokes.
That glazing method explains the extended timeline. Each glaze needs time to dry before the next, and Leonardo kept adjusting. He blended edges so gradually that no hard outlines remain on the face, a technique called sfumato. Sfumato requires repeated thin layers, and each round of refinement adds weeks or months. The result is the soft, smoky transition from forehead to cheek that defines the face.
Infrared and X-ray studies reveal multiple underlayers and changes beneath the visible surface. Researchers have found evidence of a different initial pose and shifted outlines in the underpainting. This means Leonardo reworked the composition, not just the surface. Reworking a panel portrait in oil is slow because corrections sit on top of dried glazes and demand careful blending.
One counterintuitive point: the famous smile may not be a single decision but an artifact of layered revision. Because Leonardo blended so gradually, the expression shifts depending on where the viewer's eye lands. That is a property of the painting technique, not a hidden code.
Quantified Context: Scale, Time, and Labor
The numbers around the portrait are modest but telling. The panel measures about 30 by 21 inches, so the whole painting fits within roughly 630 square inches of surface. A typical glazed oil portrait of this size might involve dozens of thin layers. Leonardo's known habit of slow, iterative work fits a multi-year timeline more than a single campaign.
| Comparison item | Approximate figure or date |
|---|---|
| Panel dimensions | 30 x 21 in (77 x 53 cm) |
| Medium | Oil on poplar panel |
| Likely start | Around 1503 |
| Later refinements | Into the 1510s, possibly to about 1517 |
| Move to France | Around 1516 |
| Current location | Louvre, Paris |
| Typical portrait glaze layers | Dozens of thin applications |
The panel's age is around 500 years, which matters for conservation. Poplar warps with humidity changes, and a 500-year-old thin panel is sensitive to temperature and moisture swings. The Louvre controls climate closely for this reason. The painting's stability today depends on environmental control, not just the original materials.
Edge Cases and Competing Interpretations
Not every scholar accepts the same start date. Some push the beginning slightly later, to 1504–1506, arguing that Leonardo's other projects delayed the portrait. Others argue the sitter is not Lisa Gherardini at all, though the 1503 Vespucci note and later scholarship support the Lisa identification for most experts. The date range itself is the safer claim than any single year.
There is also a distinction between when the portrait was started and when it reached its final state. A painting can be "begun in 1503" and still be adjusted years later. Museums often give a range for this reason. Treat "painted" as a span, not a moment.
A professional caveat: radiocarbon dating of the wood gives the age of the panel, not the painting campaign. Dendrochronology can estimate when the wood was cut, but it cannot date brushstrokes. Science constrains materials, while documents and connoisseurship constrain timing. The two lines of evidence must agree, and here they broadly do.
Red flag: sources citing a single precise year like "1503" as the completion date are oversimplifying. Red flag: claims that the painting is definitively "finished in 1506" ignore the later French period. Red flag: treating radiocarbon results as a painting date confuses panel age with artistic work. Red flag: unsourced viral posts claiming a hidden second portrait beneath the surface overstate the evidence.
Misconceptions About the Timeline
The most common misconception is that the Mona Lisa was painted quickly in one burst. The layered glazes and documented reworking make a short single campaign unlikely. A second misconception is that Leonardo "finished" it at a specific moment; the panel seems to have stayed with him, and final touches may have come late.
Another myth is that the painting is huge. It is a small portrait, smaller than many people expect when they see reproductions. That small size made it portable and allowed Leonardo to carry it to France. Scale and timeline are linked: a small portable panel could travel, which shaped its history.
People also assume the Louvre display reflects how it was always seen. For centuries the portrait was a private or courtly object, not a public icon. Its fame grew much later. The date of painting and the date of fame are separated by centuries.
Practical Actions for Evaluating Date Claims
If you want to assess a claim about when the Mona Lisa was painted, follow a few concrete steps. Check whether the source gives a range or a single year, because reputable art-historical writing usually gives a range. Look for named documentary evidence, such as the 1503 Vespucci note or Vasari's account, rather than vague assertions.
Verify whether the source distinguishes panel dating from painting dating. Wood analysis can suggest when the poplar was cut, but not when Leonardo applied paint. Ask whether the claim accounts for the painting's presence in France around 1516, which implies work continued or at least that the panel was retained.
Use a threshold for trust: accept a range of roughly 1503–1517 as the mainstream scholarly span, and treat narrower claims as needing explicit citation. Compare at least two authoritative sources before repeating a date. Museums and peer-reviewed art-history publications carry more weight than general websites.
Limitations of the Evidence
The historical record has real gaps. No contract for the Mona Lisa survives, and no dated inscription exists on the panel. Vasari wrote decades after the fact and included details that don't match the painting. The 1503 note confirms a portrait was underway but does not mark completion.
Scientific analysis adds material facts but cannot read intention or timing from a brushstroke. It can show revisions and layering, which support a long campaign, but it cannot produce a calendar date. The consensus range is therefore an inference from converging evidence, not a measurement.
Readers should also be careful with reproduction-based claims. Many online images are color-corrected or cropped, which can mislead comparisons of brushwork. The safest position is that the Mona Lisa was begun around 1503 and worked on over roughly the next 14 years, with the exact boundaries still debated.