The Church of San Francesco is dedicated to St. Francis, a resident of Assisi. Construction began sometime after the saint's death in 1226, its purpose to mark his burial site and to serve as the mother church of the Franciscan Order he established. The building consists of an upper and lower church, both with a Latin cross plan with aisleless nave, transept, and apse. The naves feature a four-partite vault system and the lower basilica also includes side chapels. As the structure was erected with papal support and needed to reflect the power and wealth of the papacy, it is quite ostentatious and therefore at odds with the Franciscans' vow of poverty. The interiors in both churches are richly ornamented with frescoes executed by the most important masters of the 13th and 14th centuries who were either from Rome or somehow connected to the papacy. In the upper church, Cimabue was responsible for the apse and transept decorations (after 1279), the first featuring scenes from the life of the Virgin to whom St. Francis was especially devoted and the second the Crucifixion, Apocalypse, and lives of Sts. Peter and Paul. In c. 1287, Cimabue's pupil, Giotto (some question the attribution) painted 28 scenes from the life of St. Francis taken from St. Bonaventure's Legenda Maior, considered the official biography of the saint. Some of the vault frescoes in the upper church that depict scenes from the Book of Genesis have been attributed to Jacopo Torriti and dated to the 1290s. In c. 1328, in the lower church, Simone Martini frescoed the Montefiore Chapel with scenes from the life of St. Martin. During the same decorative campaign, Pietro Lorenzetti contributed scenes from the Passion (1325-1330) in the lower church transept. These treasures mark the Church of San Francesco as one of the most important landmarks of the Proto-Renaissance era.
Historical dictionary of Renaissance art. Lilian H. Zirpolo. 2008.