It has its origins in a "modern" town-planning scheme designed by the Counts Fieschi, feudatories of Varese Ligure in the 12th century, following their victory over other noble families who wanted to control the territory, a strategic crossroads connecting the area of Parma with the eastern Ligurian coast.
The Fieschis wished to build a town that could also be a fortress; hence the elliptic plan on which the houses were built, rigorously in stone with no openings to the outside, except for the two original gates, of which the Sottana gate is still visible.
The moat and walls were built after the completion of the Borgo.
The Fieschis shared the building expenses with wealthy local families.
The economic effort made it possible for craftsmen and merchants to participate in the construction of a common undertaking. In the small square, which originally did not have the "median" houses, there used to be a market.
The two-storey houses facing the square all looked alike: the ground floor under the porches was destined for storage or workshops, while the top floor was used as living quarters.
The Fieschis also built a church dedicated to the Virgin Mary, which was probably located in the building that now houses the library. Among the "median" houses worth mention is the so-called Casa della Ragione or Casa del Capitano, probably used as a court of justice in the middle of the 16 century, after an unsuccessful plot against the Fieschis. A mullioned window with two lights is still visible.