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 situation at that time. Another debatable point is Thietmar's claim that Mieszko "subordinated himself to the King". Most historians believe that it was only a matter of recognition of Otto's royal authority. Some suggest that a fealty relationship could in fact be involved. Whether or not the German-Polish invasion of Bohemia actually happened, the friendly relations between the Czechs and the Poles came to an end. Bohemia resumed its earlier alliance with the Lutici, which caused in 990 a war with Mieszko, who was supported by Empress Theophanu. Duke Boleslav II was probably the first one to attack. As a