"He supported the missionary goals of Adalbert, Bishop of Prague, and Bruno of Querfurt. The martyrdom of Adalbert in 997 and his imminent canonization were used ...
to consolidate Poland´s autonomy from the Holy Roman Empire. This perhaps happened most clearly during the Congress of Gniezno (11 March 1000), which resulted in the establishment of a Polish church structure with a Metropolitan See at Gniezno. This See was independent of the German Archbishopric of Magdeburg, which had tried to claim jurisdiction over the Polish church. Following the Congress of Gniezno, bishoprics were also established in Kraków, Wrocław, and Kołobrzeg, and Bolesław formally repudiated paying tribute to the Holy Roman Empire. Following the death of Holy Roman Emperor Otto III in 1002, Bolesław fought a series of wars against the Holy Roman Empire and Otto´s cousin and heir, Henry II, ending in the Peace of Bautzen (1018). In the summer of 1018, in one of his expeditions, Bolesław I captured Kiev, where he installed his son-in-law Sviatopolk I as ruler. According to legend, Bolesław chipped his sword when striking Kiev´s Golden Gate. Later, in honor of this legend, a sword called Szczerbiec ("Jagged Sword") would become the coronation sword of Poland´s kings." - (en.wikipedia.org 31.01.2020)
