Roskilde Abbey or Our Lady's Abbey was a monastery of nuns dedicated to Saint Mary the Virgin. It was founded in the early 12th century for Benedictine nuns, but in 1177 became part of the Cistercian reform movement.
It was chiefly known for the tomb of Saint Margrethe or Margaret of Ølsemagle or of Højelse (both names of places near Køge), who, although murdered by her husband, had been wrongly buried as a suicide on the beach at Køge. After miracles were declared to have happened round her grave, her remains were moved to the Abbey Church, the Vor Frue church, in 1176 by Absalon of Lund, Bishop of Roskilde, a kinsman of Margrethe; he arranged for the construction of a suitable shrine in the church, and transferred the nunnery to the Cistercians in the following year. Despite Absalon's best efforts, and also despite the local veneration, Margrethe was never formally canonised. The shrine was nevertheless later declared a place of pilgrimage by the Pope, and the nuns were allotted one third of the income generated by it. Despite all efforts, however, the center of the cultus remained the small chapel built near Margrethe's original grave on the beach.
The abbey was suppressed in 1536 during the Protestant Reformation in Denmark. Around 1600 the convent buildings and the eastern half of the church were demolished. Today the former abbey church has a beautiful furniture from the 17th century.
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.