sentences:  Otto III of Brandenburg raided Warmia and Natangia, forcing the locals to surrender.The peace talks that begun in 1247 achieved little, but a new truce was arranged in September 1248 and peace was made on November 24, 1248.Swantopolk had to return lands seized from his brothers, allow Teutonic Knights to pass through his domains, stop charging tolls on ships using the Vistula, and stop any aid to the Prussians.