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 of Poland from the second part of the name *Dago-mierz, since the merger in pronunciation of "sz" with the devoiced "rz" which would appear in this position is quite recent. However, some historians believe that the word "Dagome" is a melding of two names: the Roman Catholic "Dago," for "Dagobert" (Mieszko's hypothetical baptismal name), and the Slavic "Me," for "Mieszko." The Latin word "iudex" ("judge") would be used in the meaning of "prince." Another interpretation is that "Dagome iudex" is a corruption of "Ego Mesco dux" ("I, Prince Mieszko"). Mieszko I took over the tribal rule after his father's death ca. 950–960,