The province of Terni is characterized by its slopes encountered along the path of rivers, allowing the exploitation of hydro catchment areas, so as to have led to the creation of several artificial lakes: In the 2nd millennium BC the province was occupied by a population called Umbri, who founded the cities of Amelia, Narnia Nahars, Otricolum and Interamna Nahars.

One of the most important and richest Etruscan cities in province of Terni was Orvieto and an unidentified place called Fanum Voltumnae.

For centuries, Umbrian and Etruscan fought hard for the rule of the Tiber Valley, until, in 299 BC when Roman legions began the invasion of Umbria.

In 571 the Lombards, after invading the Po Plain, went down the Apennines and, in 575, founded the Duchy of Spoleto in what is now Umbria and the neighbouring areas; this state remained formally independent until 1250.

In 1527 Terni was used a camp of the Landsknecht army that would subsequently take part in the Sack of Rome and fought at Spoleto and Todi, where the League of Cognac troops were located.