It was built in 1265, outside the ancient Roman city. Together with Palazzo Trecchi and the church of Sant'Agata, it formed the nucleus of the new urban expansion in medieval times, desired by the “popular” faction, as opposed to the “notables” faction, which had its centre in Piazza del Comune.
Inspired by the architecture of the Palazzo Comunale, it stands on the square with a two-storey façade: the lower storey consists of a portico with Gothic arches and the upper storey is made of brick and crowned with battlements, with four triple lancet windows illuminating a single large room.
Throughout the 13th century, the “Consiglio della Città Nova” met here; in the following centuries, its function ceased and the palace became the headquarters of the fustian merchants' guild, then a barracks, then the seat of the notarial archive, with modifications accompanying the changes in function. Restored at the end of the 20th century, it is now used for conferences and events.