The building complex was most likely built after a major city fire in 1369. The oldest part of the building is the southern main building, where the famous Kurfürstensaal (Elector’s State Hall) is located. The Kurfürstensaal, which is decorated with Gothic wall frescoes, was the scene of ceremonial acts of state, such as the election of the Bishop of Chur in 1417 and the official swearing of allegiance to the Holy Roman Emperor by Dietrich von Erbach, Archbishop and Elector of Mainz and Chancellor of the Roman Holy Empire, in 1435. The liberal party, FDP, was also founded there. The main building also shows a corner chapel and there is a Gothic stair tower.