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. With defence in mind, the castle had pyramid and single pitch roofs with several towers and gates. The round window openings and friezes in the solid walls made the castle an artistic highlight of the Upper Danube valley.
No building remains of note have been left behind from the 13th and 14th centuries. Only in the 15th century did a new building period begin at the castle under the eminent and architecturally-minded Count of Werdenberg. The Werdenbergs expanded the building to the north-east. Only the lintel engraved with the year 1498, which is part of the Swedish Tower, now remains. A few years later, the building was expanded to the west.
The third building period began during the time of Count Charles II of Hohenzollern-Sigmaringen (1576-1606). Under the supervision of master builder Hans Alberthal of Dillingen, the castle underwent widescale transformation between 1627 and 1630 and went from being a castle to being a Renaissance château.
In around 1650, the two separate buildings from the Werdenberg period were brought together under one roof by master builder Michael Beer of Au in the Bregenz Forest.
Only minor renovation and building work was carried out during the 18th century. The ancestral hall was established within the castle in 1736 (renovated in 1879). During the years 1860/1880, neo-Gothic style changes were made under royal master builder Josef Laur. The castle was extensively redesigned following the great fire of 1893 during which almost the entire castle was destroyed. The work was carried out by royal architect Johannes de Pay and primarily by Munich architect Emanuel von Seidl in a historicist or eclectic style.
The Portuguese Gallery, which encloses the inner courtyard of the castle on the side facing the city, was completed in 1902 and marked the end of this period of alterations.References:
Frösöstenen is the northern-most raised runestone in the world and Jämtland's only runestone. It originally stood at the tip of ferry terminal on the sound between the island of Frösön and Östersund. The stone dates to between 1030 and 1050. It has now been relocated to the lawn in front of the local county seat due to the construction of a new bridge, between 1969 and 1971, on the original site.
Frösö runestone inscription means: Austmaðr, Guðfastr's son, had this stone raised and this bridge built and Christianized Jämtland. Ásbjörn built the bridge. Trjónn and Steinn carved these runes.