The City Hall has been located in this place since the 14th century, well away from the seat of the former ruler, the Prince-Bishop, who resided on Cathedral Hill. This separation shows that the burghers of the town, with their then growing economic strength, sought independence from the bishop. It was also the craftsmen organised into 15 guilds who in 1501 carried through the council's decision to join the Swiss Confederation. To this occasion, at the beginning of the 16th century the front part of the City Hall was replaced by a new building. The battlements were adorned with the emblems of the 12 cantons that then constituted the confederation along with Basel.

At the beginning of the 17th century the Rathaus was enlarged and the facade was adorned with mock architecture by Hans Bock. In 1900, the wing on the extreme left and the tower on the right were added to the Rathaus. At the same time the old rear building from the 14th century was demolished and replaced by a new structure.