The Museum of the Swiss Charters of Confederation (Bundesbriefmuseum) was built in 1936 as a national shrine for the Federal Charter of 1291, which was believed to be the founding document of the Swiss Confederation. Today, the museum explains the national myth and the actual history of the Old Swiss Confederacy. It features a collection of original documents and flags.
The overwhelming Spiritual national defence of this period vanished over time. The Federal Charter of 1291 is no longer seen as Switzerland's founding document. Other documents have been given equal importance. Beginning with the exhibition design of 1999, the museum began to integrate the latest historical findings. Since 2014, the myth surrounding the Federal Charter is an important part of the current permanent exhibition, while the architectural setting of the 1930s remains present.
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.