The Duomo of Siena’s floor is now open to visitors and will be until October 24th. Most of the year just a few of the 56 panels are visible. The rest are covered by pressboard planks and carpets to protect the unbelievably beautiful inlaid marble mosaics from the pitter patter of a million pairs of tourist feet a year, but for the next two months people will be dazzled by a floor unlike anything else in Italy or, I daresay, the world.
The 56 mosaic panels cover the entire floor of the cathedral. Although there are decorative geometric and floral elements, what makes this floor so startling are the figures: scenes from the Bible, Hebrew and Christian (mainly the former); allegories about fortune and ancient philosophers; the ten Sibyls of antiquity representing the revelation of Christ to virtuous ancient peoples; and symbols of Siena and its Ghibelline allegiance, like a portrait of Holy Roman Emperor Sigismund (my favorite HRE) conferring with his advisers. The panels are rectangles, rounds, hexagons, squares and rhombuses.
The cartoons would be made on paper first by prominent local artists (or in one special case, by Umbrian master Pinturicchio), then they would be translated to marble mosaic format by stone cutting, carving and marquetry masters. The earliest panels were made using the graffito technique where lines were scratched into the surface of white marble and then filled with pitch or bitumen to make them black. Later panels used different colors of marble to create intricate inlays complete with delicate shading and strong chiaroscuro contrasts.
According to 16th century artist and biographer Giorgio Vasari, Sienese master Duccio di Buoninsegna first designed the floor mosaics in the early 1300s. He did design the Duomo’s stained glass round window in 1288 and its altarpiece in 1308 (both are now in the cathedral museum), but there’s no evidence that he had any involvement or that it started that early at all. The first records of payments made to artists for the floor date to 1369. The earliest panels are the Wheel of Fortune (1372), the Sienese She-Wolf Surrounded by the Emblems of Allied Cities (1373) and the Imperial Eagle (1374). They were restored in the 1860s with many of their marble inlays replaced, worn nearly featureless by centuries of tramping pilgrims and tourists.
Work continued throughout the 15th century, with panels depicting the Four Virtues, the feats of King David, Joshua and Samson, my man Emperor Sigismund and a gorgeous Death of Absalom. In the 1480s, the 10 Sibyls were created and two large transept panels with shockingly vivid images of The Slaughter of the Innocents and The Expulsion of Herod.
Starting in 1517, Mannerist painter Domenico Beccafumi, considered the greatest Sienese artist of his time, took the lead in designing the floor. He worked assiduously for the next 30 years, creating the central hexagon panels in the transept depicting various episodes in the life of the prophet Elijah, plus the rectangular frieze 26 feet long showing Moses Striking Water from the Rock on Mount Horeb, Moses on Mount Sinai and The Sacrifice of Isaac.
Beccafumi was also an innovator on the mosaic inlay side of things. Here’s how Vasari describes his work in his Lives of the Artists:
The figures and scenes were already in great part designed on the marble, the outlines being hollowed out with the chisel and filled with a black mixture, with ornaments of coloured marble all around, and likewise the grounds for the figures. But Domenico, with fine judgment, saw that this work could be much improved, and he therefore took grey marbles, to the end that these, profiled with the chisel and placed beside the brilliancy of the white marble, might give the middle shades; and he found that in this way, with white and grey marble, pictures of stone could be made with great perfection after the manner of chiaroscuro. Having then made a trial, the work succeeded so well in invention, in solidity of design, and in abundance of figures, that he made a beginning after this fashion with the grandest, the most beautiful, and the most magnificent pavement that had ever been made; and in the course of his life, little by little, he executed a great part of it.
By the end of Beccafumi’s contribution, the floor was basically complete. After him, some minor elements were added, some damaged pieces restored with exact copies, and in 1878, artist Alessandro Franchi created new Elijah panels to replace irretrievably damaged 15th century pieces which didn’t match Beccafumi’s Elijah theme. Franchi’s panels don’t mimic Beccafumi’s style, but they’re very much in keeping with it.
If you just can’t make it to Siena over the next couple of months, you can at least peruse the extensive collection of pictures of the floor on Wikimedia. They need to get Villanova University’s computer squad on the case so they can make one of those high resolution 3D composites like they did with the Sistine Chapel.