Mieszko Bolesławowic I Herman. Mieszko was forced to leave his country and his education behind and seek refuge at the friendly court of Ladislaus I of Hungary. The king of Hungary was apparently very fond of young Mieszko and treated him like a son. Following the death of his father in 1081, Mieszko remained in Hungary until 1086 when he is known to have returned to his homeland. There are two conflicting versions explaining the circumstances of this return. Chronicler Gallus Anonymus simply states that Mieszko was peacefully summoned to Poland by his uncle Władysław I Herman. It is likely that this
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