A predecessor of current Oberhausen palace was a medieval castle about 200 meters away from today's location. This 12th or 13th century building has now completely disappeared. In 1443 the moated castle controlling an Emscher River passage fell to the von der Hoven clan based in the fiefdom of Kleve. In 1615, Overhus then passed on to become the domain of Conrad von Boenen. The castle was often plundered and seized due to its advantageous position at the important Emscher transition, as took place in the Eighty Years' War for example.
In the late 18th century Oberhausen was left to decay. In 1801 it was leased to Maximilian Friedrich Graf von Westerholt-Gysenberg and daughter-in-law Friederike Karoline von Bretzenheim, the illegitimate daughter of the Bavarian-Palatinate elector Karl Theodor. Because the neglected castle was deemed inappropriate for their social status, Maximilian Friedrich commissioned the architect August Reinking in 1803 to draw up plans for the renovation and extension of an approximately 200-metre-long inn and posting station to the north-west of the castle to become a neoclassical manor house. Schloss Oberhausen was constructed and fitted out according to these plans as a noble place of residency between approximately 1804 and 1820/1821. From 1808 the landscape architect and Dusseldorf court gardener Maximilian Friedrich Weyhe designed the manor house park and gardens.
In 1983 the collecting couple Peter and Irene Ludwig established the Ludwig Institut für Kunst der DDR (Ludwig Institute for Art of the German Democratic Republic) in Oberhausen with a permanent loan of 500 works dedicated to East German art, and brought with them works from Bernhard Heisig, Wolfgang Mattheuer, Willi Sitte and Werner Tübke. In 1996 Peter and Irene Ludwig initiated a new concept for the location in the form of the Ludwig Galerie Schloss Oberhausen.
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.