ENThe article considers the events of the siege of Polotsk in 1381 during the struggle for power in the Grand Duchy of Lithuania after the death of Grand Duke Olgerd. Crusader knights from German lands participated in the siege of the city as part of the troops of the Livonian Order. The use of new sources made it possible to reconstruct the campaign, reveal the names of its participants and tentatively estimate the number of the crusader detachment. Two mentions of Polotsk in the German sources of the 14th century are introduced into the East European scientific discourse for the first time. These mentions demonstrate the resonance caused by the events of the “Polotsk War” in the German lands; they also show the importance of Polotsk as a political center in the Baltic Sea region. Keywords: Polotsk, Grand Duchy of Lithuania, Livonian Order, Mark and Cleve Counties, Crusades, “Reysen”, chivalric poetry, visual sources.