Frederick Barbarossa deals with the problems on the northeastern border of the Holy Roman Empire. There, King Władysław, Barbarossa’s ally, has been ousted by his brothers and replaced by Bolesław IV, who refuses to pay the annual tribute of 500 silver marks. The Teutonic Knights, under Frederick’s leadership, forcefully overcome the enemy barrier and reach the Oder River. In open battle, the Teutons are unbeatable, and Bolesław must submit, pay a fine of 3,220 silver marks, and agree to participate in the subsequent military campaign in Italy, a policy that will be implemented by the next ruler, Władysław.
