 In the same year he solicited the Emperor Frederick Barbarossa in the Imperial Diet of Goslar for possession of Plötzkau, which passed to him in 1173.However, a dispute over the rule of the Plötzkau lordship sparked a fierce conflict with the Welf duke Henry the Lion that led to the destruction of Aschersleben and Gröningen and nearly resulted in the destruction of Halberstadt.Bernhard nonetheless was able to confirm his possessions.