Casimir I the Restorer not supported by modern historians. Regardless, he left church work for good in 1031. Casimir's father, Mieszko II, was crowned King of Poland in 1025 after the death of his father Bolesław I the Brave. However, the powerful magnates of the country feared a strong central government like the one that existed under Bolesław I's rule. This led to considerable friction between the King and the nobility. Taking advantage of the King's precarious situation, Mieszko II's older half-brother Bezprym and younger brother Otto turned against him and allied themselves with the Holy Roman Emperor Conrad II, whose forces attacked Poland
Mieszko I, Duke of Cieszyn the Přemyslid dynasty in the person of Wenceslaus III, son and successor of Wenceslaus II. On 5 October 1305, Mieszko obtained his major victory when his daughter Viola Elisabeth married King Wenceslaus III. This union was a chance for Mieszko to make himself one of the most powerful figures in Bohemia, and he even began some attempts to obtain the Polish crown. However, Mieszko's promising career ended suddenly with the murder of Wenceslaus III (Olomouc, 4 August 1306). Viola Elisabeth never bore Wenceslaus III any children and the Přemyslid dynasty became extinct. After 1306 the political activity of Mieszko almost