The first traces of  human presence in the Trebbia valley go back to the Neolithic period as the flint axe found near Rovegno at the beginning of 900 proves. This small axe is mint and perfectly smooth and it is not the only relic found in a territory rich of historical traces which draw attention to the importance of this district as a connection between the coast and the Po hinterland.
A Bronze Age axe and dagger have been discovered during excavations in the Bobbio area, but most of the relics and the first certain historical data go back to Roman period.
Our mountains were inhabited by the ancient tribe of the Liguri. They used to live a hard life surviving thanks to rudimentary agriculture, to hunting and  sheep farming.
The funds of Cognolo "Coloniolum" and  Fognano "Faunianus", the discoveries of axes, in proximity of Pietranera, terracotta pieces and fragments of tools in bronze are witness to the Roman presence. Roman and Ligurian settlements were present as per headstones and votive objects discovered in various parts of the valley: a small bronze appeared during excavations carried out on  Mount Alfeo in 1955 at about half a meter under, representing a young offerer by the elegant and classical shapes.
The Trebbia Valley district is not directly interested by the main Roman arteries, the Aemilia Scauri (Aurelia) which winds along the coast and the Emilia which  runs along the axle Parma-Piacenza, both remained unchanged over the years; there are smaller roads which follow the valley or lead off from it, putting in connection the plain with Ligurian coastal towns and with Tuscany; concerning Patrania road, the ancient pedestrian road leading to the Trebbia Valley, only hypothesis can be made.
The main historical trace connected to the Roman presence refers to the Trebbia River battle, fought during the second Punic war  at the end of 218 a.c. among Annibale’s Carthaginian soldiers and the Romans.
The Romans were led by the consul Sempronio on the high grounds on the right side of the river to south of Piacenza. The discovery of elephant tusks brought here by Annibale’s troops, makes us suppose that Punics colonies descending from the soldiers settled on the left side of the river. Later they were included under Piacenza’s jurisdiction which was extended onto the Po area during the Roman imperial epoch.

When the Romans gave up administrating the area , a dark period followed of which no traces have remained. In the 17th century the developing of Bobbio’s monastery  threw new light on the history and on the development of the human settlements. The monastery was funded in 614 by the Irish monk Colombano on the ruins of an ancient temple devoted to St. Peter and at the confluence of the Trebbia River and Bobbio. The location of the monastery was very important: set in advanced position towards Liguria which was  in Byzantine hand and being the passage between Liguria and Esarcato , it offered many possibilities of communication and expansion for the Byzantines . The same was for  the Longobards who had the possibility to communicate with the Tuscia through the Trebbia Valley, being the roads through Ligurian territory  inaccessible.
As a matter of fact from the Trebbia Valley the ancient road follows the Aveto river course through steep gorges, it crosses the eastern side of Mount Fascia, it passes Villa Cella and gets into the Sturla valley which goes down towards Chiavari hinterland, where the monastery had many possessions.  Instead Liguria is connected by a route which runs  parallel to the course of the Trebbia River in the highest part in the valley and it goes on to Piacenza along an itinerary studded with monastic possessions such as Travo, centre of a vast “Bobbio” court.
After the end of the Longobard kingdom in 774 by hand of Carlo Magno, the monastery enhanced with new territories: close territories, big areas in the Aveto valley and  possessions extended over the Po plain,  Pavia, Mantova and Ravenna became part of the Convent’s properties.
Monks’ activities was fundamental for the agricultural colonisation of the valley and for cultural development which made an important village out of Bobbio. For many centuries monks’ activities had been influenced the Trebbia Valley development but once got the Episcopal dignity and formed the diocese a period of decadence began for the monastery culminating in 1795 when the famous library codes were dispersed and some of them transferred to Rome and Turin.
After Carlo Magno’s death the empire shattered and the Saracens, at first stopped by the presence of such a powerful interlocutor, got to reach the Ligurian hinterland in search of loots. Another factor featuring The Trebbia Valley’s history is the Malaspinas’ dominion.
The marquises who had their residence in  Oramala fortress in the high Staffora Valley took possession of the territory around the year 1000. From then on the historical stories of the valley mixed with those of families who had had the dominion for centuries . The marquises Malaspina, descending by the Obertengos, marquises of Tuscany, in the Trebbia Valley affirmed their influence on Bobbio’s area and Rivalta.
Malaspinas’ dominion was not peaceful: threatened by the city of Piacenza, they tried to conquer St. Colombano monastery’s territories in Bobbio and St. Paul’s territories in Mezzano, nevertheless the low valley remained under Piacenza and the Anguissolas, while the Malaspinas kept the territories south to Bobbio.
The alternate historical events, along with  excessive asset subdivisions with consequent struggles among branches of the same family, brought to the disintegration of  possessions.
Currently the Malaspinas’ castles in Zerba, Carana, Castel del Lago, Campi, Brugnello are completely in ruin and nothing is left of them. Towards the half of the 13th century new Lords appear: the Fieschi Earls from Lavagna whose territorial expansion grew  proportionally to the growth of their political importance.
The Fieschis had succeeded  to the Malaspinas for a span of over three centuries: in 1505 the Fieschis purchased the possession of Croce and right after also  the Cariseto castle from the Malaspinas.
Due to the failed attack against Andrea Doria by hand of Earl Luigi Fieschi, the latter lost his whole wealth which were given to the Dorias.
The Dorias started again their expansionistic politics in the Trebbia Valley and by 1540 they had conquered the castle and the Ottone fief, in 1583 Casanova’s fief, in 1651 Fabbrica’s fief and in 1695 the Frassi one.
The old vassals were slowly replaced by  Genoese rich families of merchants who aspired to get a new social prestige through acquisition of noble titles. This situation only lasted till 1815 when the Vienna Congress abolished imperial feuds and decreed new Lords decayed and gave the territories to the Sardinian Kingdom.
The analysis of historical events shows as the territory of the  Trebbia Valley was bound up to the Lombardy, under Pavia Province and to Piacenza rather than Liguria. Nowadays this is evident in dialectal inflexions closely connected to the Italian language which show traces of Piacenza dialect influences.