Assisi, a medieval city built on a hill, is the birthplace of Saint Francis, closely associated with the work of the Franciscan Order. Its medieval art masterpieces, such as the Basilica of San Francesco and paintings by Cimabue, Pietro Lorenzetti, Simone Martini and Giotto, have made Assisi a fundamental reference point for the development of Italian and European art and architecture.
The Roman plan of the city is based on the set of terraces, the construction of which started in the north-eastern part of the town (close to San Rufino), then extending toward the west. Culturally, the region belonged to Umbria but was on the border with Etruria. Abundant archaeological evidence, in fact, shows that the city's foundation relates to the Umbrian phase, being later taken over by the Romans. The Roman monuments include the Temple of Minerva dating from the 1st century BCE to the time of Augustus, as part of an important sanctuary in the forum area, as well as theatres, bath-houses, and other public buildings. The ancient city walls were about 2300m long, enclosing some 55ha with vast green areas. The extent of the settlement and the fact that it was granted the status of municipium in 89 BCE demonstrate not only its role as a religious centre but also its political and economic significance. From the 3rd century CE, the city shows little evidence of construction until the beginning of the new millennium. Even so, the site continues being associated with religion, and the development and diffusion of Christianity are elements that deeply characterize the scenario, also closely associated with the ancient rituals and therapeutic treatments linked with water. The first Christian martyrs were killed in water, according to a legend, Bishop Rufino being one of them.
After the period of the barbarian invasions, which caused a considerable reduction in population, the regional layout of Assisi is characterized with the affirmation of Christianity, involving ancient sites associated with water and martyrdom. Water in fact becomes the symbol of life after death and its control takes on a liturgical nature. The territory is marked by the linkages between monastic and religious centres, settlements (eg San Vittorino, San Benedetto), and hermitages (eg Le Carceri). The region was subject to profound changes from the 11th and 12th centuries with the change of land ownership from important patrons to the classes of artisans and merchants. It also meant new types of cultivation and deforestation in view of new dynamism in development. A series of castles were built on the margins of the valley, and others were developed as centres of pastoral culture in the mountain region. In addition, there were new rural settlements, including the characteristic Umbrian building type of tower house, which remains a feature of all Assisi iconography until the present day.
Through the period from the 11th to the 14th centuries, the ancient town of Assisi was subject to important changes. The development focused on four main points: Piazza del Mercato, Murorupto, Santa Maria Maggiore, and San Rufino. The market becomes the centre of noble families, as well as having various churches (San Nicolo, San Paolo, Sant'Agata). The bishop's citadel was built close to the ancient cathedral of Santa Maria Maggiore, and San Rufino became the new cathedral in the 11th century, rebuilt in the 13th century. The walled area was enlarged in 1260 and 1316, showing an increase in population.
The most important event in the history of medieval Assisi was undoubtedly the life and work of Francis of Assisi (1182-1226), who initiated the Franciscan Order, one of the most influential monastic orders in the Christian world, and who was canonized in 1228. Francis was born in Assisi and, although he travelled a great deal, some of the key references to his faith are in Assisi, including the grottoes of Le Carceri, San Damiano, and the Porziuncola, where he died. His companion, Clare, later canonized, founded the sister order to the Franciscans. After the canonization of Saint Francis, it was decided to build a monumental church in his honour, involving the Church of Rome as well as the City of Assisi. This construction was followed by the Basilica of Santa Chiara to honour Saint Clare.
The construction of the Basilicas of San Francesco and Santa Chiara represented a new input to the urban form of the town, and gave the relatively small medieval settlement a completely new physiognomy. This included the development of the main square over the former forum area with the Temple of Minerva. The construction of the Basilica of San Francesco, in particular, changed the earlier Franciscan symbol of humility into an exaltation of the figure of the saint, and the order thus affirmed its mission in the world. The city walls were once again enlarged in the 14th century, when also the fort, La Rocca, on the top of the hill was rebuilt as part of a series of castles to protect the interests of the papacy in the region.
The social and political events from the 15th to the 18th century left their traces in Assisi, in the form of new construction and improvements in management and draining of arable land. In the 14th and 15th centuries, Assisi was involved in wars with Perugia and in conflicts with Guelphs and Ghibellines, and the city suffered from sacks and fires. Through this period, however, the symbolic importance of Assisi in relation to Saint Francis continued. The first detailed town plan that has survived till today dates from 1599, by Giacomo Lauro, indicates Assisi as the patria of Saint Francis. In the late 15th century the most important urban project was the construction of the public squares in front of the Basilica of San Francesco,. In the 16th century Galeazzo Alessi designed the large basilica of Santa Maria degli Angeli down in the valley, and it became a shelter for the Porziuncola of Saint Francis. He also restructured the cathedral of San Rufino and designed the tabernacle for the lower church of the Basilica of San Francesco. In the 17th and 18th centuries the city continued developing and a number of noble families built their palaces in the Baroque style. This period also included the church of San Francesco Converso by Giacomo Giorgetti in the 17th century.
In the 19th century, the discovery of the bodies of Saint Francis and Saint Clare gave new vigour to construction activities, including the restructuring of the convents of S. Damiano and S. Maria di Rivotorto. There were also some changes in the centre of Assisi, including the new postal offices in the Piazza del Comune. After World War II the renewed interest in Assisi provided an incentive for the protection of the historic town and its surroundings. In 1954, Assisi received the first conservation master plan in post-war Italy. At the same time, the entire municipal area became subject to nature protection.