Mieszko I Tanglefoot brother Vladimir, Duke of Olomouc, son of Otto III Detleb. They had five children: Mieszko I Tanglefoot Mieszko IV Tanglefoot () (ca. 1130 – 16 May 1211) was Duke of Kraków and High Duke of Poland from 1202 and from 9 June 1210 until his death. He was also Duke of Silesia from 1163 to 1173 (with his brother as co-ruler), Duke of Racibórz from 1173 and Duke of Opole (as Mieszko I Tanglefoot). He was the second son of Władysław II the Exile by his wife Agnes of Babenberg, daughter of Margrave Leopold III of Austria and half-sister of
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