Mieszko I of Poland one version of the legend of St. Wojciech it is written that Mieszko I had his daughter married to a Pomeranian prince, who previously voluntarily "was washed with the holy water of the baptism" in Poland. The above information, as well as the fact that Bolesław lost Western Pomerania, suggest that the region was not truly incorporated into the Polish state, but only became a fief. This conjecture seems to be confirmed in the introduction of the first volume of the chronicles of Gallus Anonymus concerning the Pomeranians: "Although often the leaders of the forces defeated by the Polish duke
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