Probably built in the first half of the 12th century (although some legends say it was built in the 9th century), Sandiás Castle was located over a castrum (Celtic settlement). It participated in the Portugal secession wars (12th century). In 1386 it was assaulted by the duke of Lancaster, pretender to the Castile crown. In the 15th century it was demolished by a popular riot, and rebuilt later. It was a meeting point for troops in the wars with Portugal in the 18th century. There are many legends about this castle.
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.