Mieszko I, Duke of Cieszyn Mieszko and his two brothers Casimir and Przemysław. Mieszko eventually swore homage to King Wenceslaus II, although the exact date was still debatable; the most accepted date by historians was 11 August 1292. Despite his alliance, Mieszko didn't take an active part in Wenceslaus II's campaign against Władysław I the Elbow-high in 1292; however, he put his army at the King's disposal and later took part in the Battle of Siewierz. Mieszko was present at the coronation of Wenceslaus II as King of Poland in Gniezno in 1300. After the death of Wenceslaus II in 1305, Mieszko continued to support
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