In ancient times prior to the Roman Empire, the Northern municipality of Demonte in Italy was inhabited by the Ligures. Along with the Sturra Valley, Demonte was conquered by the Roman legions of Marcus Quintus Flaccus and were all aggregated into the town of Pedona which today is known as Borgo San Dalmazzo and the Vermenagna and Gesso valleys.
The valley has always been important due to its strategic location by the routes which ensure easy access to the other side of the Alps.
In the 5th century, the Demonte valley was invaded by the Theodoric Goths, the Byzantines, the Franks and the Lombards. During the IX and X centuries, further invasions by the Saracens bough mass destruction and massacres to Demonte. The Saracens also dug up the entire valley in search of the minerals which the area is known for.
Later the valley fell into the control of the Bishop of Turin who controlled the area until 1150.
In the 12th century Demonte was ruled by the Saluzzo Marquisate, and in 1214 it became a municipality.
The House of Anjoy seized the entire area in 1259 and later annexed it to Provence.
Two noble families are linked to the history of Demonte – the Bolleris and the Borellis.
The Bolleris first entered Demonte in 1372 when Franceschino Bolleris conquered the castle in the town and chased away the House of Anjou Viscontes of Milan. He was then declared Royal Vicar.
In 1377 Viscount Franceschino Bolleris was appointed Lord and settled into the Angevin fortress in Demonte.
In the next years, the House of Savoy repeatedly attacked the valley in order to take control, and so in 1437 Viscount Ludovico Bolleris asked for a right to place his family crest on the emblems of the House of Anjou from his allies in Angevin. This managed to deter the attacks until in 1588 the House of Savoy managed to conquer Demonte.
After the castle was destroyed by the Savoys, they built a new fortress and a new manor which today is known as Borelli palace.
The area was frequently hosting troops who were passing during the war of Austrian succession and the numerous Napoleon campaigns.
In 1796 Napoleon beat the army of the House of Savoy and they were forced to sign the Cherasco peace treaty and surrender the County of Nice and Savoy and to demolish the fortress of Demonte and the walls of Cuneo.