Apse

   A semicircular or polygonal projection in a church, usually covered by a half-dome. Though apses can be found at the end of the transept arms or in the chapels of a church, most commonly they protrude from the building's east end and serve to house the main altar. As focus during the mass and other ceremonies, the apse walls are many times decorated with mosaics or frescoes meant to enhance the religious experience. An example of apse mosaic decoration is Jacopo Torriti's Coronation of the Virgin (c. 1294) at Santa Maria Maggiore, Rome. Examples of apse fresco decorations include those by Cimabue in the Upper Church of San Francesco, Assisi (after 1279), and by Fra Filippo Lippi in the Cathedral of Spoleto (1466-1469), both depicting the life of the Virgin, as well as Melozzo da Forli's Christ in Glory in the Church of Santi Apostoli (1481-1483; destroyed), where he introduced the di sotto in sù technique to Rome.