The defensive character is of symbolic and decorative value, only. Originally, the house was probably the seat of royal administrators (ministeriales). No documentary evidence of an association with the Counts of Nassau. Since 1581, the house has belonged to the Schlüsselfelder family (since 1709, when the family died out, foundation house). The two lower storeys date from the early 13th century. The upper storeys, including the chapel oriel and the crenel-lated parapet with octagonal corner turrets, were added 1422/33. 
In 1431, King Sigismund mortgaged his crown to the owner of the house, Ulrich Ortlieb, for a credit of 1500 guilders. Consequently, Ortlieb had the stone balustrade embellished with the coats of arms of emperor, pope, electoral princes, Nürnberg, etc.