The Abbey of Sainte-Trinité (the Holy Trinity), also known as Abbaye aux Dames, is a former monastery of women. The complex includes the Abbey Church of Sainte-Trinité. The abbey was founded as a Benedictine monastery of nuns in the late 11th century by William the Conqueror and his wife Matilda of Flanders as the Abbaye aux Dames ('Women's Abbey'), as well as the Abbaye aux Hommes ('Men's Abbey'), formally the Abbey of Saint-Étienne. The works began in 1062, starting from the rear and finished in 1130. Matilda, who died in 1083, was buried in the choir under a slab of black marble.
The original spires were destroyed in the Hundred Years' War and replaced by less striking balustrades in the early 18th century. The community of nuns were dispersed and suppressed by the French Revolution. In 1823 the local city council decided to transfer the ancient Hôtel-Dieu (possibly also founded by William the Conqueror, but more likely King Henry II of England), to the former cloister for use as a hospital, and the canonesses regular, who had assumed responsibility for the hospital from the two abbeys during the 14th century, established themselves there. The canonesses continued to operate there until 1908 when the facility was given to the Hospice Saint-Louis for use as a nursing home. The vault was demolished and rebuilt in 1865. The church was last restored between 1990 and 1993.
The façade has two large towers on the sides, each with doors leading to the aisles. The pediment of the central bay echoes the nave roof. The tympanum of the central portal depicts the Trinity and the four apocalyptic beasts, symbols of the Four Evangelists.
The nave is flanked by pointed arches surmounted by a gallery (triforium) which supports the groin vault, the first of this type built in Normandy (1130). The transept, in the centre of the church, houses the main altar. The northern transept is in Romanesque style, opening over a small apse (the chapel of the Blessed Sacrament) which houses the tabernacle. The southern transept is characterised by Gothic columns integrated within the Romanesque decoration. The choir ends with an apse decorated by four columns and a gallery with fantastic figures. Also present is a crypt in honour of Saint Nicholas.
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.