ENThe Great Northern War was an event that changed not only the Polish-Lithuanian Commonwealth, but also the countries of Central Europe. The conflict brought many tactical and strategic changes that can be observed on the battlefields and during the campaign. Therefore, it seems appropriate to refer to the battles that took place during the Great Northern War. Such a battle is the clash between the Swedish-Lithuanian and Lithuanian-Russian troops, fought near Jakobstadt (Kryżbork) on 26 July (5 August) 1704, during which Lithuanian troops were present on both sides. Kazimierz Jan Sapieha was on the Swedish side, and Michał Serwacy Wiśniowiecki was supported by Russian troops. This article collects and analyzes every available account of the course of the Battle of Jakobstadt, from each participating side: Swedish, Russian, Sapiehan and Lithuanian. The article compares these source materials and presents the most probable course of this clash in 1704. Keywords: Grand Duchy of Lithuania, Commonwealth, Sweden, Russia, battle, Great Northern War, Jakobstadt, Kryżbork, Kazimierz Jan Sapieha, Michał Serwacy Wiśniowiecki.