The ruins of a fortified settlement, identified as Castello de Petra Albella are on top of Monte Petralvella. It’s not easy to pinpoint this castle properly, it could be both the first Panicale or the first Paciano settlement. It is possible, though, that this was a very ancient castle from which both the Panicale and Paciano castles came from.

The ancient fortified town of Paciano, known as Castrum Paciani, was located halfway up on Monte Petralvella, slightly more uphill compared to where it is now. Some ruins in the the woods and a tower called Torre d’Orlando, in a private property, are all that remains of the original settlement.

The name comes from latin: Paccius, which was probably the name of the landlord who owned the territory where the curtis lived. The curtis usually consisted of a very small settlement with a few huts, governed by a single man and surrounded by a simple fence. The first time this place was mentioned is in a document written by the Emperor Berengario I in 917, where the curtes of Paciano and Panicale were donated to the Marquis Uguccione di Bourbon.

The distinction between the old and the new Paciano, the current historical center, was clear only at the end of 1200, when the new town was mentioned for the first time. The reasons why they felt the necessity to move it downhill is still unknown.

New Paciano, which is how the new castle was named, was built downhill with a trapezoidal layout. Its three main streets run parallel in an almost regular criss-cross pattern. This shape is the result of a very precise study and planning, with the intention to create something new and controlled, while the old town, built on top of a hill, probably had a typical structure with concentric walls, with the Torre Castellana at its center on an elevated position.

In 1288 new Paciano was known as Villa Paciani, a name which implies the absence of defensive walls. The walls were built in the 14th century and Paciano became castrum, which means “fortified town”.

In 1416 Paciano was conquered, together with the surrounding castles, by Braccio da Montone, and he owned it till his death in 1424.

At the beginning of the 16th century the town became property of the Papal State and it was donated to Conte della Staffa from Perugia by Pope Clement X.

In 1798 Paciano was part of the first Roman Republic, leaving the Papal State for a short while.