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
Mieszko I of Poland which facilitated the development of trade. Amber, fur and salt (extracted in Kuyavia and around Kołobrzeg) were exported to other countries, while cloth, crafts, tools and ornaments were imported. According to Gallus Anonymus, before becoming a Roman Catholic Mieszko had seven pagan wives, whom he was required to relinquish, leaving Dobrawa as his only spouse. Nothing is known of the fates of any possible children from these relationships. In 965, before his baptism, Mieszko married Dobrawa (b. 940/45 – d. 977), daughter of Boleslav I the Cruel, Duke of Bohemia. They had two children: According to one hypothesis there was