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
Spytihněv I, Duke of Bohemia Spytihněv I, Duke of Bohemia Spytihněv I (c. 875 – 915), a member of the Přemyslid dynasty, was Duke of Bohemia from 894 or 895 until his death. He was the eldest son of Duke Bořivoj I, the first historically documented Bohemian ruler, and his wife Ludmila. Spytihněv and his younger brother Vratislaus were still minors at the time of their father's death about 889, and the Bohemian lands were placed under the regency of their suzerain, the Great Moravian ruler Svatopluk I. After Svatopluk died in 894, an inheritance conflict arose between his sons Mojmír II and Svatopluk II.