Founded by the Etruscans of Volsinii (Orvieto) in the 6th century BC.

Rome, having won the decisive battle with the Etruscans here in the two battles of Lake Vadimone (309 and 283 B.C.), elevated it to a municipium in the early 1st century B.C. The territory is dotted with villas, which benefit from the transit to Orte of the Via Amerina and the important river port of Seripola, which was reinforced in the Augustan age.

 

The affirmation of Christianity, with the elevation to bishopric in the early 7th century, and the addition of fortifications by the Byzantines, are some of the signs of Orte's growth in the Tiber area in the early Middle Ages. After having been disputed for a long time by the Lombards, in order to secure control of the main roads connecting Rome and Ravenna, it experienced further development in the mid-9th century, with the foundation of a second cathedral (later Santa Maria Assunta) and the strengthening of the walls.

 

Occupied by the Arabs and reconquered in 914, it intensified its control over the river in the 10th and 11th centuries, contending for supremacy with Amelia, Narni and the Abbey of Farfa. This was the beginning of the city's most prosperous period, which increased its surface area with the development of suburban villages and incorporated the bridge over the river around 1150.