Tuscania, like many neighboring towns, is situated on seven headlands tuff, located between the rivers “Marta” and “Capecchio”, overlooking the valley of “Marta”, an important road that connected, since prehistoric times, the Lake of “Bolsena” with the Tyrrhenian Sea. The etymology of the city is quite transparent. The Romans called the city "Tuscana", from "Tuscia" ("Etruria"); thus, "Tuscana" was "the city of the Etruscans”. Secondiano Campanari, in the nineteenth century, noted that " [...] really, from 'tuscaniensis' [" inhabitant of Tuscana "] should come 'Tuscan-i-a' and not 'Tusc-a-na', but it is certain that, in ancient times, this town was called both ways [...]" (see Secondiano Campanari in “Giornale Arcadico di Scienze, Lettere ed Arti” ["Arcadian Journal of Sciences, Letters and Arts"], Rome, 1837, p. 50). Campanari then adds that in medieval times it was also called "Tuscanella" and "Toscanella," perhaps to avoid confusion with the Region of Tuscany.

In Etruscan times, settlements consisted of small villages, gathered in an area called "Tusena". With the Romans, the city grew significantly; in fact, it developed the production of terracotta and increased its necropolis. After the Social War (90-88 BC), Tuscania was later erected in Roman "municipium" and assigned to the tribe called “Stellatina”. In the fifth century AD, it was one of the first bishoprics in Italy and it remained so until 1653. With the collapse of the Roman Empire, Tuscania underwent various barbarian invasions, and it was subsequently occupied by Heruli, Goths and Lombards, who conquered it. In 774 the city was occupied by Charlemagne (742-814), who ruled it until the donation to Pope Adrian I (700 ca.-795), so that in 781 it became part of the Church State. From 967 to 1066 it was subject to the family of “Anguillara”; from 1080 it was owned to the “Aldobrandeschi”, and, later, to the Marquis of Tuscany.

During the Middle Ages it became an independent municipality, surrounding numerous castles and fortifications, Frederick II of Swabia (1194-1250), finally, managed to conquer it. In 1222 St. Francis of Assisi (1182 ca.-1226) lived in Tuscania, event after which followed one another construction of numerous monasteries in the surrounding. At the beginning of XIV century also the city name changed, from "Tuscania" to “Tuscanella”.

In 1421 Pope Martin V (1368-1431) entrusted it to the captain of fortune to Angelo Broglio da Lavello, called the “Tartaglia” (1415), who ruled it until the advent of Anjou, in 1495. Then it followed the fate of the Church State until its annexation to the Kingdom of Italy, in 1861.