They were built by the Counts of Biserno of Gherardesca family, lords of the castle of the same name near San Vincenzo, in the mid-1200 when they came to Massa and were counted among the citizens of the City. Infact, in the 13th century, the feudal lords who became citizens of Massa had the obligation to have a house in the City. When Massa lost its independence, the Counts left Massa and the building passed to the Bishops who established their home here after the selling of the Castle of Monteregio in 1336 to the garrison of Siena. It was the residence of the Bishops until 1603, when it was exchanged for the house of the Opera San Cerbone, next to the Cathedral, where the Bishop still resides. Next to the building, separated by a thin slit, the tower rises. The tower was later incorporated into the Town Hall. Already in 1300 a very small part of the tower was sold to the municipality.