Mieszko I of Poland at Gniezno, Poznań, Ostrów Lednicki and elsewhere. The existence of the missionary diocese emphasized the individuality and independence of the Polish state. At the time of the reign of Mieszko, there was no single place serving as the capital, instead, he built several "palatiums" around his country. The most important locations were Poznań (Ostrów Tumski), Gniezno and Ostrów Lednicki. The latter was a ring-fort some 500 meters in circumference, containing the country's first monumental architecture, a stone palace used as the duke's residence. The Catholicization also led to political changes. The emergent power structures were independent of the traditional tribal
Mieszko I of Poland Mieszko allied his country with Sweden against Denmark. The alliance was sealed with the marriage of Mieszko's daughter Świętosława with the Swedish king Erik. The content of the treaty is known from the not entirely reliable, but originating directly from the Danish court tradition account given by Adam of Bremen. In this text, probably as a result of confusion, he gives instead of Mieszko's name the name of his son Bolesław: Mieszko decided on the alliance with Sweden probably in order to help protect his possessions in Pomerania from the Danish King Harald Bluetooth and his son Sweyn. They may