Bohemian–Polish relations had worsened following the death of the wife of Mieszko and Bohemian princess Dobrawa in 977; this marked the end of the Polish-Bohemian alliance.

[1] Until the mid-980s the rulers of both the Polish and Bohemian states supported the Holy Roman Empire's Henry II, Duke of Bavaria, but their alliance did not last into the second half of that decade.

[2] The war was fought likely for the purposes of territorial expansion, with Polish ruler duke Mieszko I taking over the lands of the Vistulan tribe (Lesser Poland area, with the major settlements of Sandomierz and Kraków) in the years 998–999.

[3] The Bohemian duke Boleslaus II contested Mieszko's actions, and their armies clashed in Silesia.

[5][8] Thietmar, however, while devoting some space to the conflict itself, did not discuss the reasons for it, which modern historians can only speculate about.