Count Wilhelm II of Katzenelnbogen built the Katz Castle in the second half of the 14th century. Katz Castle was used as bastion and military base to protect the Rheinfels Castle. Together they formed a fortified bulwark with a barrier for levying of the Rhine toll. The extended view up to the bend of the river at the Loreley was also of great importance to secure salmon fishing. Due to the intentionally chosen location on the mountain ridge Katz Castle could not possibly be conquered from the valley.
Only after the invention of fire arms, Katz Castle had to be substantially reinforced. It was also upgraded as bastion against Maus Castle in the Electorate of Trier. At the same time the donjon of Katz Castle was raised to to ensure eye contact with Reichenstein Castle. In 1479 the family line of the Counts of Katzenelnbogen died out.
In succession of long-lasting disputes on heritage, Katz Castle and Rheinfels Castle were besieged, demolished, rebuilt and extended several times. Even though repairs had been made in 1800, Napoleon blew up Katz Castle in 1806.
In 1896 District Administrator Berg acquired Katz Castle, to reconstruct it as close as possible to the original design. From 1946 till 1951 Katz Castle served as local High School 'Institut Hofmann' including board
Since 1989 Katz Castle is private property of a Japanese and accommodates the hotel Katz Castle.
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.