As part of the Military History Library, the AST publishing house begins publishing a series of books on the history of the Civil War in Russia. This topic in our country has so far been covered, although widely, but still not fully and objectively. In addition, many publications published in the 20s and 30s of the 20th century have long become a bibliographic rarity, and emigrant literature was inaccessible to our readers. This volume is dedicated to the war with Poland in 1920, as a result of which Russia lost the western lands of Ukraine and Belarus and was obliged to pay Poland 30 million gold rubles. The book was written immediately after the war and was later not subject to censorship, it uses unique archival documents, is equipped with maps and detailed appendices and will be of interest to lovers of military history.