 This castle had probably been built by them around 1100.In this period they came into military conflict with the counts of Northeim, who around 1105/1110 had defeated Count Rugger (Rüdiger) I of Bilstein and destroyed the first, still weakly fortified Bielstein Castle.His successor, Rugger II of Bilstein, asserted himself with the construction of the new Bilstein Castle and began to develop the land around the castle, the woods on the Hoher Meißner, as, as "clearing demesne.