Collevecchio is located between the Tiber Valley and the Sabine Mountains chain on the border with the Umbria region. Its origins date back to the Sabine period and a large necropolis was found here. With the decadence of Rome and the arrival of the Lombards, in 570 Collevecchio was part of the Duchy of Spoleto.
Its history has been poorly documented until 1253, when Pope Innocent IV authorized the inhabitants of a settlement called ‘Castrum Mozani’, located in a very unhealthy place to move to the area of Collevecchio.
In 1283 it became part of the municipality of Narni, and had approximately ‘700 inhabitants and 126 homes’. By 1368 it was a fiefdom of the Orsini and Anguillara families.
Between 1605 and 1621 Pope Paul V chose it as the seat of the Apostolic governorship of Sabina and here were built the court, prisons and records office.