17. All injuries, losses, and damages which we or our followers have sustained from the league or any of its members or allies are hereby pardoned, and all such transgressors are hereby received back into our favor. 18. We will not remain longer than is necessary in any city or bishopric. 19. It shall be permitted to the cities to erect fortifications within or without their boundaries. 20. It shall be permitted to the league to maintain its organization as it now is or to renew it as often as it desires. 110. The Formation of the Duchy of Austria, 1156. Wattenbach, Die ost. Freiheitsbriefe; Doeberl, IV, no. 31 a. The nobles of Germany early showed the desire to free themselves from the control of the emperor and to acquire independence at the expense of the crown. The document by which Frederick I created the duchy of Austria out of the Bavarian east mark and gave it to his uncle, Henry, contains some concessions which tended to weaken the crown. Instead of binding the new duke closely to the crown and compelling him to render services commensurate with his high position, the emperor excused him from attending diets which were not held near his lands, and from military service except in the lands which adjoined his. He also gave the duke the complete administration of justice in his territory. Other princes were not slow to demand similar privileges, and the crown was gradually stripped of its powers and prerogatives. See nos. 136, 139, 153, 160. The duchy of Austria, created by this grant, came into the possession of the Hapsburg family, and formed the centre of the Hapsburg lands, the present Austro-Hungarian empire. See no. 150.