[3] Boleslaus II took over the rule of the Duchy of Bohemia as kníže (a title that may be translated either as duke or prince) on his father's death in 972.

In 992, he approached King Otto III and participated in an unsuccessful campaign against the Lutici tribes in the wake of the Great Slav Rising of 983.

Nevertheless, the Bohemian diocese was placed at that time within the jurisdiction of the Archbishop of Mainz, and Emperor Otto II enforced the appointment of the Saxon monk Thietmar (Dětmar) as first bishop.

On 28 September 995, Boleslaus' forces and the confederate Vršovci clan stormed Libice Castle in southern Bohemia and massacred the members of the Slavník dynasty that were found there.

The internal struggles of the Přemyslid dynasty shook the Bohemian duchy until Duke Oldřich's efforts stabilised the country.