As the Bard Fortress, Champorcher Castle also belonged to the powerful Lords of Bard, until the fratricidal war between William and Hugo in 1212. Little is known of this early building: we know that it was burned down by order of Hugo of Bard, which might suggest that it was constructed mostly of wood, like many buildings in the late Middle Ages. It was probably reconstructed in the same century, and definitely before 1276, when already it needed to be roofed with wooden tiles.
Following the popular tradition, the castle was built on the Corseria (currently the sacristy), with a chapel that would later become the first parish church.Of the ancient building, it remains the square-plan tower (about six metres per side) with swallowtail merlons south-west of the church. It was used during the Middle Ages as a watchtower. Access is via a door which is can only be reached using a ladder placed four metres above the ground.
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.