Before 500 AD East Germanic tribes dominated the area, who later on emigrated to the west. The then very rural region was thereafter scarcely populated by Slavic peoples until the 12th century. Remains of a Slavic castle can be found in the town of Rerik (which still bears a Slavic name). In 1160 Henry the Lion conquered the region; afterwards German monks, peasants and traders arrived to settle here. In the Middle Ages the region profited from the vicinity of the wealthy Hanseatic city of Rostock. The worst time in regional history was the Thirty Years' War, which depopulated the area almost completely.