Mieszko I, Duke of Cieszyn disappeared. Is unknown why this happened, because at that time he was only around fifty-years-old and was still considered young enough. The government of the Duchy was increasingly absorbed by his sons Wladyslaw and Kazimierz. The only sign of his political activities during this time was the lease of the Czech city of Kęty to the Bishop of Kraków, Jan Muskata, a strong opposer to the rule of Władysław I the Elbow-high in Greater Poland. However, in contrast to his brother Bolko I, Mieszko didn't support the Rebellion of wójt Albert in 1311. Mieszko was known for his generosity to
Mieszko I, Duke of Cieszyn shelter to the Bishop in Raciborz. His politics against Henry IV were reinforced when the Duke of Wrocław repudiated his wife Constance —sister of Mieszko— and sent her back to her homeland. Another consequence of Mieszko's politics was an armed expedition of Henry IV in 1287 against Racibórz, who was sieged. Then Mieszko was forced to refuse his help to the Bishop. In 1290 the division was made of the Duchy of Racibórz: Przemysław retained Racibórz and Mieszko obtained the rule over the districts of Cieszyn, Oświęcim and Zator. The first time that he signed himself as Duke of Cieszyn