Küssaburg

Küssaburg is a hilltop castle in the municipality of Küssaberg, Germany, constructed by medieval German lords.

Archaeological finds and early hypotheses point to human use of the hill in Roman times, including the possibility of a Roman watch or signaling tower nearby, and the presence of a Gallo‑Roman sanctuary and a Roman country house in the surrounding area. A written reference to a castle on the hill appears in a monastery archive for the year 888, while other documentary evidence places construction of the medieval castle likely between about 1125 and 1141.

In the 12th century the site is linked with named individuals and local noble families. Heinricus de Chussaberch is recorded in the years 1135 and 1150. Werner von Küssenberg served as abbot of St. Blasien from 1170 to 1178. Over the following centuries the lordship passed through several hands: in 1241 Bishop Heinrich von Tanne of Constance is recorded as acquiring the lordship, around 1250 the counts of Lupfen appear as heirs, and later the counts of Sulz became holders, among them Rudolf V von Sulz. In 1703 the castle came by marriage into the possession of the princes of Schwarzenberg, and it remained in that family until the Klettgau region was acquired by the Grand Duchy of Baden in 1812.

Military action affected the castle on several occasions. During the Swiss War of 1499 the garrison surrendered on 20 April 1499, and the castle was later returned to the count of Sulz. During the 1525 peasant uprisings of the region, known as the peasants’ war, local peasant forces from the Klettgau besieged the fortress unsuccessfully, and Sulz forces carried out punitive measures. Following those events the castle was enlarged from 1529 with funds provided by Austrian authorities so it could serve more as a fortress with a standing garrison.

On 8 March 1634, in the chaos of the Thirty Years’ War, the castle was destroyed by fire. That destruction has often been reported as the garrison deliberately burning the complex when Swedish troops neared, while other contemporary evidence records operations by a detachment of a Swedish commander in the area and entries in period diaries. Later accounts record a landslide on 25 December 1664, though a geological assessment placed that event about two kilometres away from the ruin.

After the 1634 conflagration the castle remained a ruin and was used as a source of building stone by local people until the middle of the 19th century; legal measures ended removal of masonry in 1855. That same year provisional protection and access works began. Archaeological investigation began in the late 19th century with systematic excavations in 1896–1897, and a thorough clearance of the ruins was carried out between 1932 and 1939. Ownership of the site passed to the district authority Landkreis Waldshut in 1978, after which a sequence of conservation projects was carried out, with large expenditures during the first fifteen years following transfer. A restored gatehouse with a working wooden drawbridge was completed in 1981, the mechanism was adjusted in 1996, and the current drawbridge version dates from May 2017. A new conservation and sanitation plan was developed in 2018 with detailed works and funding foreseen. The south slope of the hill is designated as a nature reserve and the ruin is formally listed as a historic monument. The castle’s name was later used as the name of a steam locomotive on the Basel–Konstanz railway when that connection opened on 15 June 1863.