Like medieval cartoon strips, 56 marble intarsia (fancy artist word for inlay) cover the 1300 m2 floor of the towering duomo. Crafted by a variety of artists through the 14th to 16th centuries, 600 years of foot traffic have made them sufficiently fragile that the valuable marble carpet spends most of the year covered in fibreboard panels but for a couple of months in later summer, the full majesty of the mosaic floor is unveiled as it would have appeared in the Middle Ages.Unsurprisingly, the scenes primarily document Old Testament stories though messages from famous philosophers such as Socrates and proud stories of Sienese history (Siena was supposedly founded by the son of Remus) are also detailed. Near the altar where marble mosaic techniques reached a crescendo, stunning light effects involve cartoons themed around Moses including the superb Moses on Mt Sinai (where Moses receives the Ten Commandments) with near luminescent three-dimension effects by subtle use of varying shades and grades of marble.
Remarkably, the progression in artistic technique can be easily seen – earlier methods involved scratching away the marble and filling it with pitch for simple black and white mosaics while latter works involved full inlaying techniques with a rich palette of red, green, white, grey and black marbles all tracked to quarries from nearby areas (including the famed Carrera marble).
While familiar biblical stories abound, an overheard guide remarkably explains that Jesus isn’t included in any of the floor panels.Some mosaic tiles are hexagonal in shape seamlessly interlocking under the giant cathedral apse. No religious mildness or understatement is tolerated in the shockingly vivid images of The Slaughter of the Innocents and Expulsion of Herod while another tells of the battle between David and Goliath. While the mosaic floor is remarkable the dizzying black and white marble stripes on the walls and columns overwhelm the mind. Columns fronting the nave are sculpted with allegorical busts while the vaulted roof is blue in a sea of golden stars.
If you like the floor, pop into Library Piccolomini which branches off one side of the cathedral.
Built by Pope Pius III to house the extensive collection of his uncle, Pope Pius II, superb wall frescoes in radiate vibrant colours and contain many valuable historic texts (a couple of which are likely to be displayed).
The scope and intricate detail of Siena’s visual bible of medieval marble mosaics is unparalleled in the world and only unveiled in all its majestic beauty for a couple of months each year. Don’t miss this visual feast which Giorgio Vasari (Italian architect and painter) famously described as “the grandest, the most beautiful, and the most magnificent pavement that had ever been made”.