The current bishop’s palace (Episcopal) was started, more or less simultaneously with the new cathedral, in the early decades of the eleventh century: evidenced by the many walls in square blocks, which emerged during the last restoration, and slits on the eastern side likely for defensive purposes. It underwent significant renovation and expansion by Bishop Cesare Naccarato (1484-1504) who apposed his coat of arms on the front door and on the back, along which a new row of rooms was added. 

Other decorative works were led by Bishop Antonio Maria Graziani (1592-1611) who hired the architect Ottaviano Mascarino, to him we can attribute the arrangement of the entrance, the staircase to the first floor and the first setup of the Hall of Honor; this was completed during the episcopate of Gaudenzio Poli (1643-1679) who had it decorated with the first series of coats of arms of bishops, then continued by his successors until the last Bishop of Amelia, Vincenzo Lojali (1938-1966) . Other interventions are visible, inside and outside, from the numerous inscriptions by the bishops over the following centuries