Mieszko I of Poland place after Mieszko's death, specifically in 999. There is also a theory according to which during this transition period Lesser Poland was governed by Bolesław Chrobry, whose authority was granted to him by the Bohemian duke. At the end of his life (ca. 991-92), Mieszko I, together with his wife Oda and their sons, issued a document called "Dagome iudex", where the Polish ruler placed his lands under the protection of the Pope and described their borders. Only a later imprecise summary of the document has been preserved. There are two main theories concerning reasons behind the issuing of "Dagome
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