Duchy of Masovia | Siemowit II of Masovia | Janusz III of Masovia | Boleslaus II |
While Siemowit's son Duke Konrad II (1264–1294) moved his residence to Czersk he and his brother Boleslaus II entered into a long-term conflict over the Polish seniorate with their Kuyavian relatives and the Silesian Piasts, which estranged them from the Piast monarchy.