Mieszko I of Poland the Czechs took over Meissen, but in the same year Henry II gave up his pretension to the German throne. The role played by Mieszko I in the subsequent struggles is unclear because the contemporary sources are scarce and not in agreement. Probably in 985 the Polish ruler ended his support for the Bavarian duke and moved to the side of the Emperor. It is believed that Mieszko's motivation was the threat posed to his interests by the Polabian Slavs uprising. The upheaval was a problem for both Poland and Germany, but not for Bohemia. In the "Chronicle of Hildesheim",
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