The first date known of the settlement of Templars in Metz is 1133. Between 1180 and 1220 the Templars built an octagonal chapel in Roman style outside. The inside presented a ribbed vault and the nave opens on a square choir and on a little apse. In 1312, as happened for the large majority of Templar places, the preceptory of Metz fell to the hands of the Knights of St John of Jerusalem. In 1556, the chapel was converted in warehouse due to the building of the citadel. Now, a patted cross is still visible onto the lintel of the main door of the chapel.
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.