Mieszko I of Poland mentions a gift or dedication of Mieszko's land to the Pope (the act took place almost a hundred years earlier). It is roughly his borders that Poland was returned to in 1945. There is no certain information on Mieszko I's life before he took control over his lands. Only the "Lesser Poland Chronicle" gives the date of his birth as somewhere between the years 920–931 (depending on the version of the manuscript), however, modern researchers don't recognize the Chronicle as a reliable source. Several historians on the basis of their investigations postulated the date of Mieszko I's birth to have
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