Mieszko II Lambert Gniezno Cathedral. Contemporary German chroniclers considered this to be an abuse of power on the part of the Archbishop, which was made necessary by the existing political situation. After his father's death, Mieszko inherited a vast territory, which in addition to Greater Poland, Lesser Poland, Silesia and Gdansk Pomerania also included Western Pomerania, as well as Lusatia, Red Ruthenia and territory of present-day Slovakia. Whether Moravia was still under his reign or was lost earlier is disputed. Once his solo reign had begun, as an important Central European ruler, he was now very important to the Holy Roman Empire. Later
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