Bogisław, now sole ruler of Pomerania-Stolp, began a lengthy quarrel with Bishop Nicholas of Cammin about several ecclesiastical estates, which led to Nicholas' expulsion and the appointment of Magnus of Saxe-Lauenburg in 1410. Like his brother Barnim, Duke Bogisław also entered into King Jogaila's service, but changed sides in 1407/08, when he allied with the Teutonic Knights under Grand Master Ulrich von Jungingen and settled their common border. Nevertheless, Bogisław refused any armed support and when the Knights lost the Battle of Tannenberg in July 1410, he changed sides again and allied with Poland in return for the Bütow, Schlochau, Preußisch-Friedland, Baldenburg, Hammerstein and Schivelbein areas, which Poland had gained from Teutonic Prussia before. This, however, was cancelled according to the First Peace of Thorn in 1411.