Poland to form into a recognizable unitary and territorial entity around the middle of the 10th century under the Piast dynasty. Poland's first historically documented ruler, Mieszko I, accepted Christianity with the Baptism of Poland in 966, as the new official religion of his subjects. The bulk of the population converted in the course of the next few centuries. In 1000, Boleslaw the Brave, continuing the policy of his father Mieszko, held a Congress of Gniezno and created the metropolis of Gniezno and the dioceses of Kraków, Kołobrzeg, and Wrocław. However, the pagan unrest led to the transfer of the capital
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.