 And probably at the turn of 1327/1328, the sons of Siemowit of Dobrzyń – Władysław the Hunchback and Bolesław – exchanged the principality of Dobrzyń for the principality of Łęczyca.In 1329 there was a resumption of warfare.John of Luxembourg, with the help of the Teutonic Knights, took Dobrzyn, which he soon gave to his allies.