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 I of Poland copying the document he made a mistake and wrote down Dagome instead of Dagomer or even Dagomir. The name Dagomir is used to this day and its construction is similar to other Polish names like for example: Władimir/Włodzimierz or Casimir/Kazimierz. The evolution of the "-mir" element to "-mierz" is due to two separate developments: first, the regular change of the vowel "i" to "(i)e" before "r", and second, the modification of the nominative case by the vocative for certain names (hence, Kazimierz replaced Kazimier based on the vocative Kazimierze). It is debatable whether the name Mieszko is a nickname formed