After Duke Casimir IV was killed while fighting for the Polish inheritance against his Piast cousin Prince Władysław the White three years later, Bogisław became co-ruler of Pomerania-Stolp, together with his brothers Wartislaw VII and Barnim V. As a younger son, Bogisław possibly had prepared for an ecclesiastical career and suspiciously eyed the appointment of John Brun, chancellor of Wenceslaus IV of Bohemia, then king of Germany, as Bishop of Cammin in 1386.

The reign of Bogisław and his brothers in Pomerania was influenced by the ongoing conflicts between his eastern neighbours, the Kingdom of Poland and the State of the Teutonic Order.

[2] When their brother Wartislaw VII died in 1395, Bogisław and Barnim V settled a treaty with Teutonic Prussia in neighbouring Pomerelia (Gdańsk Pomerania), which was in constant conflict with Poland, to safeguard their supply routes in return for financial credit.

[2] Their cousins, Duke Swantibor III of Pomerania-Stettin and his brother Bogisław VII, changed sides in 1395 and allied with the knights in return for economic aid.

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.