June 9, 1311 the City of Siena was shut down and all hands were in the streets, carrying candles and celebrating the installation of Duccio's Maesta in the cathedral. The altarpiece had been over three years in the making.
The medium is tempera on wood with gold overlays. Duccio is credited with having been a leader in the turning of Western art from the Byzantine to a more realistic representation of the artist's subjects.
More than four hundred years later, 1771, the masterpiece was sawed into pieces, dismantled, and effectively flung to the four winds. Parts of it have been recovered and reassembled, some of it finds residence in musea across the face of the Earth, and parts of it are still missing, likely shall always be missing. It is thought that cutting it up was a commercial venture, that is, to make the "parts" more saleable and more easily transported. A principal portion resides in a museum in Siena, its hometown.
Source: Masterpiece Cards and various websites.