Trevi, or Trebe (house) Umbra, as it was called by Pliny, soon became a Roman municipium including the town itself as well as the lands below towards the Via Flaminia, as testified by the large number of architectural finds at Santa Maria di Pietrarossa. During the Middle Ages the inhabitants of Trevi retreated back into the Roman fortifications (1st century BC). The new circle of fortifications that still surround the city today were not erected until 1264. The valley below remained uninhabited until the 19th century, until the land was reclaimed and a new settlement - Borgo Trevi - developed near the Via Flaminia. After a period spent as a Longobard vassal under the Duchy of Spoleto, Trevi eventually became a free city state in the late 12th century. . In 1470 the first Umbrian printing press (the fourth in Italy) was set up at Trevi. As from 1816 the extensive lands under the control of Trevi, that once included Fabbri, Fratte and Santa Luca towards Montefalco, along with Castel Ritaldi, Picciche, San Giovanni, San Lorenzo and Cannaiola, were drastically reduced.
The ancient village of Trevi is nestled into one of the last spurs of Monte Serano and it has a magnificent panoramic view. Trevi town centre is surrounded by undulating green olive groves which in some places reach right up to its medieval walls. The "Passeggiata" is a magnificent 800 m tree-lined road (close to traffic during the summer) with spectacular views onto the valley below. Cart tracks lead up to an altitude of 1000 m. in 10 minutes from where it is possible to continue for the peaks of Monte Brunette (1425 m) and Monte Serano (1429 m) with no great difficulty. The origins of Trevi are lost in time, paleolithic ruins in the area tesify an earlier prehistoric civilisation. Its importance grew in particular under Roman rule whe the old Flaminia Way was restored. In ancient times its territories covered vast areas of the surrounding hills and valleys, with fertile land around the river Clitunno and communications secured by the Flaminia; it was also a diocese till the end of the 11th century. Allied with Perugia against Spoleto, it only became autonomous in 1389 after various fights with neighbouring communes. Subsequent dominions followed, the most disastrous being the Trinci's of Foligno till 1438. It returned under Perugia and Church control and then followed the fortunes of the Papal States till the Unification of Italy. Trevi was most prosperous in the early Middle Ages and during the Renaissance Period. SIGHTS TO SEE: the Church of St. Emiliano, Patron Saint of the town. The square and tower, the focal point of town life. The Mostaccio Arch , the original entry gate to the ancient fortress. The ancient Roman Walls are still perfectly preserved in via Fantosati and in via del Fiscale.