Boleslaw I the Brave

Bolesław I supported the missionary work of Bishop Adalbert of Prague, who was martyred by the Prussians. Bolesław ransomed Adalbert's body and buried it in Gniezno. This event elevated Adalbert to sainthood and led to the establishment of the Archbishopric of Gniezno.

Holy Roman Emperor Otto III visited Gniezno for a congress with Boles

Bolesław I intervened in the Kievan Rus' succession crisis, capturing Kiev and installing his son-in-law Sviatopolk I as Grand Prince. He annexed the Cherven Cities (Red Ruthenia) into Poland, expanding Polish territory eastward. The campaign demonstrated Polish military power.

Bolesław I signed the Peace of Bautzen with Holy Roman Emperor Henry II, ending a series of wars over Lusatia and Meissen. The treaty confirmed Polish control over Lusatia and Milsko, securing Poland's western borders and recognizing Bolesław's territorial gains.

Bolesław I was crowned King of Poland in Gniezno, becoming the first crowned king of the Polish state. This coronation elevated Poland from a duchy to a kingdom, establishing its sovereignty and status in medieval Europe. He died shortly after the coronation.