Until recently very little was known about the building history of Huis Hatert. The tower was probably built in the second half of the 14th century. The west and south sides of the building show signs of walls that were once attached to the tower, which makes it likely that the tower used to form a part of a greater complex and that it served as a gate tower located on one of the corners of a lager castle. Its relatively thin walls and small size also hint at this. In later times the tower underwent great changes. Floor heights were changed, openings were blocked and new wings were attached to the tower aft er the former walls had been torn down. It is evident that one of the cellars of Huis Hatert dates back to the 16th century and one of the wings to the 18th century. In the 19th century a new gable was placed in front of the 18th century wing and tower to create a more uniform appearance.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.