Possibly built on the foundations of a Roman castrum fortress, the Moosham castle was first documented in a 1191 deed. It was seized by the Prince-Archbishops of Salzburg about 1285 and from the 14th century onwards served as the residence of an episcopal burgrave. Under the rule of Prince-Archbishop Leonhard von Keutschach from 1495, the castle was rebuilt and extended. In 1520 it became an administrative seat of the Lungau region and was besieged during the German Peasants' War of 1524–25. Archbishop Wolf Dietrich Raitenau stayed here on his flight from Salzburg in October 1611, shortly before he was captured.
Archbishop Count Hieronymus von Colloredo dissolved the Moosham bailiwick in 1790, whereafter the castle decayed. In 1886 the Austrian explorer and patron of the arts Count Johann Nepomuk Wilczek purchased the ruin and had it restored. Up to today the complex is a private property, though its rooms featuring Wilczek's extensive art collection are accessible to the public.
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.