"The castle of Sughereto or Suvereto is situated in the foothills, almost at the foot of a knoll, which dominates towards the south a large, fertile and pleasant plain…… at the present day, the castle of Sughereto is enclosed by walls with two gates and a keep". Thus Agostino Cesaretti described the castle of Suvereto in 1788.
The beginnings of the castle, are closely linked to the history of the central keep, placed "on the highest part, towards the north". Archaeological excavations carried out by the University of Siena in 1989 brought to light a series of post-holes inside the later stone keep, which, dating to the 9th century, are the earliest traces of settlement on the site.
The earliest stone structure on the site is the tower, most likely built around 1164 on the orders of the Aldobrandeschi Counts, notwithstanding the fact that at the time they were in a close rapport with the Pisan republic.
It was the Pisan Republic itself that was to build the walls of the village and the strong defensive keep on the northern side. These works were linked to altered defensive needs, along with new political ideas regarding the management of the territories of the state. The building programme was completed in 1308, as an inscription placed on the entrance to the walled enclosure bears witness. Thus there was a walled area roughly trapezoidal in form extending away from the tower and furnished with two gateways. The buildings and other amenities necessary to house the garrison of Pisan troops were placed inside this area.
The castle underwent various alterations through time until it was definitively abandoned as a defensive structure around the year 1600.
In the 19th century the building was adapted to serve as housing, a three storey building being added onto the side of the tower, within the fortified area. Towards 1950 this building was in turn abandoned and at the end of the 1980’s the area came into the ownership of the Town Council. Following the excavations of 1989-90, a programme was put in hand to restore the complex to its ancient state.