in 1147, while the hohenstaufen king conrad iii of germany was on the second crusade, conrad joined the welf duke henry the lion, as well as albert the bear and the archbishops of magdeburg and bremen to organise a crusade against the slavic obodrites and wagri tribes. in august, conrad and albert, with the bishops of magdeburg, havelburg, and brandenburg, massed their forces at magdeburg. the obodrite prince niklot and his fortresses of dubin and dimin were besieged. both he and pribislav, another obodrite prince, were forced to accept christianity and make peace.