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 I Tanglefoot to both Mieszko (who received the towns of Racibórz and Cieszyn) and Jarosław (who received Opole). In 1177 Mieszko supported his uncle and namesake Mieszko III the Old when he had to fight to maintain his rule over the Duchy of Kraków; this renewed again the disputes between him and Bolesław I the Tall, who wished to obtain the Duchy and with this the Seniorate. However, Bolesław suffered an unexpected defeat by Mieszko and his own son Jarosław, who distracted him to advance over Kraków; in his place was his younger uncle and ally, Casimir II the Just, who captured