Original sentence: From the 10th century onward, these lands were conquered by the Ottonian Dynasty and slowly Germanized, including during the Wendish Crusade of 1147.Since the early 6th century the areas east of the rivers Elbe and Saale (which had been depopulated since the 4th century) were populated by Slavic tribes called the Polabian Slavs
Edited sentence: After Charlemagne's death in 814 Saxons invaded Slavic territories, exterminating the Slavs and successively destroying their states and culture, followed in 10th century by Gero and in the 12th century by the Wendish Crusade, annihilating also the catholic Duchy of Kopnik, a vasal to Poland, which eventually became Berlin—the German capital.Since the early 6th century the areas east of the rivers Elbe and Saale (which had been depopulated since the 4th century) were populated by Slavic tribes called the Polabian Slavs, to which Charlemagne granted sovereignty in 804