Mieszko I, Duke of Cieszyn Mieszko I, Duke of Cieszyn Mieszko I of Cieszyn (, , ; also known as Mieszko I of Opole; 1252/56 – by 27 June 1315), was a Duke of Racibórz during 1282–1290 (with his brother as co-ruler) and the first Duke of Cieszyn since 1290 until his death. He was the oldest son of Władysław, Duke of Opole-Racibórz, by his wife Euphemia, daughter of Władysław Odonic, Duke of Greater Poland. Little is known about the early years of Mieszko I's life. His first documented mention was on 21 October 1258, when he appears together with his father and two younger
Mieszko the Younger point, Mieszko III decided to give the district of Kalisz to his youngest son and namesake, as his own Duchy. Mieszko the Younger died on 2 August 1193. He was buried in the crypt founded by his father in the Cathedral of St. Paul the Apostle in Kalisz. Tombstones of Mieszko the Younger and Mieszko III were found during archaeological excavations during 1958–1960. For unknown reasons, Mieszko never married or had children. On his death, Mieszko III give Kalisz to his eldest son Odon. Mieszko the Younger Mieszko the Younger (also known as of Kalisz) () (between 1160 and 1165