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 of Poland Mieszko allied his country with Sweden against Denmark. The alliance was sealed with the marriage of Mieszko's daughter Świętosława with the Swedish king Erik. The content of the treaty is known from the not entirely reliable, but originating directly from the Danish court tradition account given by Adam of Bremen. In this text, probably as a result of confusion, he gives instead of Mieszko's name the name of his son Bolesław: Mieszko decided on the alliance with Sweden probably in order to help protect his possessions in Pomerania from the Danish King Harald Bluetooth and his son Sweyn. They may