[MUSIC] Welcome back to the Age of Cathedrals. In our last time together, we began to look at the church of Notre-Dame in Paris. Notre-Dame is a Janus-faced building. It looks back to Saint-Denis, and even to some of the buildings of Normandy, like this Abbey Church of Saint-Etienne, in Caen from the 11th century. Or the Abbey of Jumièges, with their double towers and bridge. But Notre Dame is also a watershed in the development of Gothic architecture, and it presents several startling features that would be part of the cathedrals built from then on. What is new in Notre Dame? Well, first of all, Notre Dame is identifiable with the names of particular architects and master builders. And first among these Bishop of Paris, Maurice de Sully, who began building in 1163, and who died in 1196, leaving 100 pounds for the completion of the roof. Maurice's successor, Eudes de Sully, began the west facade of Notre Dame between 1197 and 1208. Guillaume de Seignelay continued the work between 1219 and 1224. Guillaume d'Auvergne supervised the installation of the large bell, named appropriately, The Bishop, between 1228 and 1249. The names of Jean De Chelles and Pierre de Montreuil are associated with the building of Notre Dame in the 13th century. As are the names of Pierre de Chelles, Jean Revy, and Jean le Boutiller in the 14th. Second innovation in Notre Dame are the flying buttresses, a move whose radical nature cannot be overstated. As we have seen, the walls of Romanesque churches were massive and had to be thick to deal with the lateral thrust of the ogival vault. Support for height was achieved from inside, from strutting over and around the tribunal. The flying buttresses of Notre Dame, however, stood outside the high walls of the choir and were perpendicular to it, but only seeming to hold it up. This wall was higher and lighter than any built before, and it transformed the old Romanesque question of weight and mass, of horizontal lintels stretched across vertical columns into one of energy, force, thrust and counter thrust. As its intricate parts with diverse functions bore the weight of the great ogival vaults, through a series of structural parries to the ground. A third innovation associated with Gothic, has to do with the structural programs all around the cathedral, but especially all across, and up and down the western facade. These are not inaccessible, but are meant to be seen, studied, taken in. Again, the entrance to the Gothic cathedral is key. I am the door, if anyone enters by me, he will be saved, we read in John 10:9. The west facade of Notre Dame is a multi-layered visual field, in which we can identify various zones, programs and sculptural media. From the high gallery of kings, to the trumeo in each doorway, to the statue-jammed figures flanking each door, to the dados reliefs below the jammed figures, to the lintels above the doors, and the tympana with their surrounding archivolts, or voussoir.