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 the Polabian Slavs. On the other hand, the supporters of the Gero's invasion theory believe that the Margrave did actually carry out a successful invasion, as a result of which Mieszko I was forced to pay tribute to the Emperor and also was compelled to adopt Catholicism through the German Church. The thesis that proposes the introduction of Catholicism as a result of this war finds no confirmation in German sources. The homage is then a separate issue, since, according to the chronicle of Thietmar, Mieszko actually paid tribute to the Emperor from the lands "usque in Vurta fluvium" (up