 During his trip to Rome, where he was sent by Bolesław Chrobry, in 1004, Unger was imprisoned in Magdeburg and probably forced by local archbishop to recognize his pastoral governance (presented in later centuries document that was proof of this cession is rather falsificate).This hypothetical recognition was used in early 12th century by Magdeburg bishops to claim rights to throne of Poznań bishops.According to known evidences Unger never return to Poland and died in Magdeburg on 9 June 1012.