The salt trade helped Eldena Abbey to become an influential religious center, and Greifswald became a widely known market. When the Danes had to surrender their Pomeranian lands south of the Ryck, after losing the Battle of Bornhöved in 1227, the town succeeded to the Pomeranian dukes. In 1241, the Rugian prince Wizlaw I and the Pomeranian duke Wartislaw III both granted Greifswald market rights. In 1250, the latter granted the town a charter under Lübeck law, after he had been permitted to acquire the town site as a fief from Eldena Abbey in 1248.