Snizort Cathedral was founded under the authority of the Archbishop of Nidaros (Trondheim) in Norway. Amongst its more famous bishops was Wimund, who according to William of Newburgh became a seafaring warlord adventurer in the years after 1147.
According to tradition, the cathedral was founded near a site where Columba had preached from a rock, which later became known as St. Columba's rock. The site may originally have been a pagan Pictish centre, but by the time of Columba's arrival may have converted to a Pictish Christian establishment. Over the early centuries of the 2nd Millennium it gained importance as the Kilmuir monastery declined and by the 14th Century was referred to as the Metropolitan Church of the Isles, being the principal seat for the Bishops of the Isles until power was transferred to Iona Abbey. It was extant until at least 1501, but destroyed during the Scottish reformation, although remains are still visible.
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.