However, the line of the Samborides became extinct upon the death of Swietopelk's son Mestwin II in 1294, and after the Treaty of Kępno, the territory became part of Poland, under King Przemysław II. The Margraviate of Brandenburg also sought to control the area and in the following armed conflict, the Polish duke Władysław I the Elbow-high called for the support of the Teutonic Knights. After expelling the Brandenburgians from Gdańsk, the Knights massacred the local population and took over Gdańsk and adjacent areas in 1308. Disregarding the Polish claims, the Order's State concluded the Treaty of Soldin with Brandenburg in the following year, where the Knights claimed all Pomerelian lands - including Lauenburg and Bütow - while the adjacent Lands of Schlawe and Stolp fell to the Ascanian margraves and were again acquired by the Duchy of Pomerania in 1316 (later Pomerania-Stolp). The Griffin dukes in 1317 also acquired the Bütow area, which was yet again sold to the Knights in 1329.