Mieszko I of Poland at Gniezno, Poznań, Ostrów Lednicki and elsewhere. The existence of the missionary diocese emphasized the individuality and independence of the Polish state. At the time of the reign of Mieszko, there was no single place serving as the capital, instead, he built several "palatiums" around his country. The most important locations were Poznań (Ostrów Tumski), Gniezno and Ostrów Lednicki. The latter was a ring-fort some 500 meters in circumference, containing the country's first monumental architecture, a stone palace used as the duke's residence. The Catholicization also led to political changes. The emergent power structures were independent of the traditional tribal
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