 This unification campaign, however, encountered considerable difficulties.In Greater Poland, Władysław managed to only take control of the Kujawy-border towns of Konin, Koło, and Nakło, because the rest of the duchy had accepted the rule of his old enemy Henry III of Głogów (except Wielun which was occupied by prince Bolko I of Opole).Pomerelia, however, became subordinate to the rule of Władysław the Short as a result of an expedition at the end of 1306, accepting tribute from representatives of Pomeranian society in Byszewo.