Greifenstein castle was first mentioned in 1158. The castle was largely destroyed in the second half of the 13th century during the wars between Count Meinhard II of Tyrol-Gorizia and the Bishop of Trent. The reconstructed castle became property of the lords of Starkenberg after the last member of the family of Greifenstein was killed in the Battle of Sempach in 1386.
Greifenstein was besieged for weeks by Duke Frederick IV of Austria-Tyrol first in 1418 and again in 1423. During the second time castle was conquered in 1426. After the Habsburg family took the possession. Today Greifenstein lies in ruins.
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.