Mieszko I, Duke of Cieszyn brothers in the consent of the foundation of a Cistercian abbey in Rudy. After his father's death in 1282, and according to the custom during the fragmentation of Poland, Mieszko and his brothers divided the Duchy of Opole-Racibórz between them: Mieszko and his youngest brother Przemysław received together the district of Racibórz as co-rulers. The other two brothers, Casimir and Bolko I, received Opole. Because Przemysław was still a minor at that time, Mieszko ruled alone until he attained his majority, in 1284. In 1285 Mieszko politically supported the Bishop of Wrocław, Thomas II Zaremba against Henry IV Probus, providing
Mieszko I, Duke of Cieszyn the church. Thanks to him, the construction was completed of the Dominican convent at Oświęcim (shortly after 1283). Also, he financially assisted the monastery of Czarnowąsy near Opole and in the Dominican of Cieszyn. Mieszko's exact date of death is unknown. Diplomatic sources suggest that he died in 1314 or in the first half of 1315, before 27 June. He was probably buried in the Dominican church in Cieszyn. In 1931 the Polish painter and sculptor Jan Raszka made a sculpture of Mieszko I in Cieszyn. According to some sources, Mieszko's wife died around 1303, but her name is unknown.