Mieszko I of Poland death occurred from causes other than natural. According to Thietmar the Polish ruler died "in an old age, overcame with fever". Probably he was buried in the Poznań Cathedral. The remains of the first historical ruler of Poland have never been found and the place of his burial is not known with certainty. In 1836–1837 a cenotaph was built for Mieszko I and his successor Bolesław I the Brave in the Golden Chapel () at the Poznań Cathedral, where the damaged remains found in the 14th century tomb of Bolesław were placed. According to Thietmar Mieszko I divided his state
Mieszko III the Old several foreign policy successes through his daughter's marriages: Elisabeth about 1173 married Duke Soběslav II of Bohemia and through the dynastic arrangement between his daughter Anastasia and the Griffin duke Bogislaw I of Pomerania, Mieszko once again reinforced Polish sovereignty over the Pomeranian duchy. In 1177 Mieszko's first-born son Odon, fearing for his inheritance, rebelled against his father. He was supported by Bishop Gedko of Kraków, his cousin Bolesław the Tall and his uncle Casimir the Just. For Odon, the main reason of his rebellion was the favoritism of Mieszko to the offspring of his second marriage and the attempts