The Artwork
What You're Actually Looking At in The Last Supper
It isn't a fresco, it began decaying almost immediately, and it survived a WWII bombing raid by chance. Here's what's really on that wall.
Check dates and availability ↗The Last Supper — key facts
| Aspect | Detail |
|---|---|
| Artist / date | Leonardo da Vinci, c. 1495-1498 |
| Dimensions | 460 x 880 cm (4.6 x 8.8 m) |
| Technique | Tempera and oil on dry plaster — not a true fresco |
| Restoration | 1977/78-1999, led by Pinin Brambilla Barcilon; unveiled 28 May 1999 |
| WWII | Refectory roof bombed 16 Aug 1943; mural wall survived, sandbagged since 1940 |
| Opposite wall | Giovanni Donato Montorfano's Crucifixion, 1495, a true fresco |
It is not a fresco — and that fact explains everything else
One of the most persistent myths about The Last Supper is that it's a fresco. It isn't. True fresco means painting into wet plaster, which bonds the pigment into the wall as it dries and is remarkably durable. Leonardo instead painted with tempera and oil directly onto two layers of dry plaster, built up from a ground of pitch, gesso, and mastic. That choice let him work slowly, revise details, and control subtle luminosity in a way fresco's fast-drying wet plaster never allows — but it meant the paint sat on the surface rather than fusing with the wall, sacrificing the durability fresco painting normally provides.
Decay began almost immediately
The trade-off Leonardo made for greater artistic control came at a real cost almost right away. Flaking was already visible within about twenty years of completion, by 1517, and a written account from 1582 describes the mural as already ruined. This wasn't a slow decline over centuries that only recent generations noticed — contemporaries and near-contemporaries were recording its deterioration within Leonardo's own lifetime and shortly after. It's a striking contrast with the enduring reputation of the image itself, and it's the direct consequence of the unconventional dry-plaster technique described above.
Painted around 1495 to 1498, on a huge scale
Leonardo worked on the mural in the refectory of Santa Maria delle Grazie across roughly 1495 to 1498. It's a genuinely large-scale work, measuring 460 by 880 centimetres — 4.6 by 8.8 metres — covering the end wall of the dining hall it was created for. Standing in front of it, the scale is part of what makes the experience distinct from viewing a framed panel painting in a gallery: it was designed as an architectural centrepiece for monks eating in that specific room, not as a portable artwork, and the room itself remains part of the experience today.
How it survived a WWII bombing raid — by chance
On 16 August 1943, an RAF bombing raid destroyed the refectory's roof and two of its side walls. The wall carrying The Last Supper itself survived, but not through any special design — the building's caretakers had sandbagged and scaffolded that specific wall back in 1940, years before the raid, as a general wartime precaution rather than a targeted effort to save the mural. Even having survived the blast, the wall stood exposed to the open air and weather for roughly two years while the refectory remained damaged, adding further stress to an already fragile painted surface.
The 1999 restoration: cleaning, not repainting
A major restoration ran from 1977/78 through 1999, led by conservator Pinin Brambilla Barcilon, and the result was unveiled on 28 May 1999. It's important to understand what that restoration actually did: it removed centuries of overpainting, grime, and earlier well-meaning but damaging touch-ups, exposing what remained of Leonardo's original surface underneath. It did not repaint or recreate lost sections. The visible result is dimmer and more fragmentary than the vivid image often reproduced in books, but it is a far more accurate window onto what Leonardo actually painted than the overpainted version ever was.
The overlooked wall opposite
Facing The Last Supper on the refectory's opposite wall is Giovanni Donato Montorfano's Crucifixion, painted in 1495 as a true fresco — and, fittingly, in far better condition than Leonardo's experimental technique across the room. Its lower corners include portraits of the Sforza family, generally attributed to Leonardo and added on dry plaster in the same fragile manner as his main work: Ludovico il Moro, Beatrice d'Este, and their sons, though these figures are now barely legible. It's easy to walk straight past this wall, but it offers a direct, visible comparison between fresco's durability and the dry-plaster technique that made Leonardo's masterpiece so vulnerable. Bare-entry tickets to see both walls are sold only by the museum itself, via cenacolovinciano.org.