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 Tanglefoot to both Mieszko (who received the towns of Racibórz and Cieszyn) and Jarosław (who received Opole). In 1177 Mieszko supported his uncle and namesake Mieszko III the Old when he had to fight to maintain his rule over the Duchy of Kraków; this renewed again the disputes between him and Bolesław I the Tall, who wished to obtain the Duchy and with this the Seniorate. However, Bolesław suffered an unexpected defeat by Mieszko and his own son Jarosław, who distracted him to advance over Kraków; in his place was his younger uncle and ally, Casimir II the Just, who captured