Man’s use of the area of the Casentinesi Forests dates back to ancient times and has always been influenced by the nearby city of Arezzo. In the Roman period, occupation of this territory intensified during the 1st century BC, during which two colonies were established. The ruins of residential settlements visible in several places at an altitude between 360 and 630 m date back to this epoch. Evidence of these sites, especially in the municipalities of Poppi and Bibbiena, can be found in areas where fictile fragments have surfaced.
From the little information available, we can deduce that, during the Middle Ages, the Clusentinum returned to the March of Tuscany, a frontier area between the communes of Arezzo and Fiesole. Between the 9th and 10th centuries, the crisis in public order and the de-structurisation of the Carolingian system of territorial government weakened the central powers and strengthened local power as a result. This was held by the bishops of Arezzo, a few lordly families and by numerous monastic foundations in the area. The Guidi, in particular, had gained power over the right bank of the River Arno. They were lords of a large portion of land extending along the entire Apennine ridge and on the Romagna side and they consolidated their estates in the Casentino area in the first half of the 11th century.
The frequency and importance of the monastic foundations in this territory played a strategic role in communications in the Apennines. During this period, the Casentino forests became mountain hermitages open to the strictest forms of obscure asceticism. The dissolution of the rights of the bishops of Fiesole in the Casentino valley preceded that of their colleagues in Arezzo and facilitated the rise of the Guidi family, who seized the main road links giving access to the Florentine area and used the fortresses of San Niccolò, Raggiolo, Montemignaio and Poppi to dominate the western side of the system of communications
The religious orders were centred on the valley roads and determined the creation of new towns to add to the territorial network of parishes along the main arteries crossing the Casentino area.
Responsible for the process of encastellation, which had given the Casentino area its turreted, military skyline, the aristocracy who had divided the territory during the early Middle Ages now bowed to the dynamic trading towns of Florence and Arezzo, and began a process that would divest their feudal power in favour of that of the communes.
The map of the political boundaries in the Casentino was altered several times during the alternating communal feuds. Bibbiena, an ancient nucleus of the Episcopal estates of Arezzo, followed in the wake of the decline of its archbishop Guglielmino Ubertini after the Ghibelline retreat at Campaldino (1289).
Following its victory at Campaldino, Florence decided to create some outposts along the Arno and founded the “new lands” of San Giovanni Valdarno, between Figline and Montevarchi, the Terranuova Bracciolini, opposite Montevarchi and Castelfranco di Sopra, between the diocese of Fiesole and Arezzo. At the same time, the Florentines refortified Montevarchi and Figline, whereas they consolidated their expansion in Arezzo in the north-eastern hollows, by strengthening the defences in Bibbiena and reconstructing the walls of the fortress in Sansepolcro in 1318.
The self-governing fiefdoms finally ended with the Florentine victory at the battle of Anghiari (1440).
The following centuries (from the 16th to the 18th) saw the consolidation of holdings and scattered settlements: villas – farms, built using urban properties, on which numerous farmsteads depended.
By the nineteenth century, a considerable demographic rise was recorded, with an increase in the town centres on the plains. New crops were introduced, such as tobacco, and traditional cultivations, such as the olive and vine, were strengthened.
In the meantime, the Casentino area became involved in the fragmentation of the large agricultural estates. In 1787, Pietro Leopoldo was appointed by Pietro Ferroni to design a “Casentino carter’s road” which was to rise from Pontassieve to the Consuma pass in order to better connect these marginal areas already used frequently by many travellers.
At the same time, a large wool factory was built in Stia along the banks of the Arno. By incorporating the fifteenth century wool and water mills, it became an economic centre of major importance for the entire area, thanks to the renowned production of Casentino felt.
Between 1879 and 1888, the Arezzo Stia railway was constructed and used for winter transhumance from the Maremma towards the Casentino area.