Viterbo (viˈtɛrbo; Viterbese: Veterbe; Viterbium) is a city and comune in the Lazio region of central Italy, the capital of the province of Viterbo.
It conquered and absorbed the neighboring town of Ferento (see Ferentium) in its early history. It is approximately north of GRA (Rome) on the Via Cassia, and it is surrounded by the Monti Cimini and Monti Volsini. The historic center of the city is surrounded by medieval walls, still intact, built during the 11th and 12th centuries. Entrance to the walled center of the city is through ancient gates.
Apart from agriculture, the main resources of Viterbo's area are pottery, marble, and wood. The town is home to the Italian gold reserves, an important Academy of Fine Arts, the University of Tuscia, and the Italian Army's Aviation Command headquarters and training centre. It is located in a wide thermal area, attracting many tourists from the whole of central Italy.
The first report of the new city dates to the eighth century AD, when it is identified as Castrum Viterbii. It was fortified in 773 by the Lombard King Desiderius in his vain attempt to conquer Rome. When the popes switched to the Frankish support, Viterbo became part of the Papal States, but this status was to be highly contested by the emperors in the following centuries, until in 1095 when it was known as a free comune.
In a period in which the popes had difficulties asserting their authority over Rome, Viterbo became their favourite residence, beginning with Pope Eugene III (1145–1146) who was besieged in vain in the city walls. In 1164, Frederick Barbarossa made Viterbo the seat of his antipope Paschal III. Three years later he gave it the title of "city" and used its militias against Rome. In 1172, Viterbo started its expansion, destroying the old city of Ferento and conquering other lands. In this age it was a rich and prosperous comune, one of the most important of Central Italy, with a population of almost 60,000.