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 Kazimierzowic no mention of Mieszko's influence on Polish politics. Mieszko died on 28 January 1065. Year of death was noted by "Rocznik kapituły krakowskiej", while day by "Necrologium monasterii superioris Ratisbonensis". He died unmarried and childless. Mieszko Kazimierzowic Mieszko Kazimierzowic ("Kazimierzowic" means "son of Kazimierz") (16 April 1045 – 28 January 1065) was a Polish prince member of the House of Piast. According to some scholars, he was probably Duke of Kuyavia since 1058 until his death. He was the third son of Casimir I the Restorer by his wife Maria Dobroniega, daughter of Vladimir the Great, Grand Duke of Kiev.