This book describes in detail the military-political situation in the Baltic region, the activities of military monastic orders, the Mongol invasion of Rus' and the countries of Western Europe. The reader will become familiar with the course of the military campaign of 1240–1242, which ended with the victory of Alexander Nevsky over the knights of the Teutonic Order on the ice of Lake Peipsi. In addition, the authors, almost for the first time in Russian historiography, attempted, on the basis of most known visual and archaeological sources, to reconstruct the appearance of the participants in the battle, to present various options for defensive and offensive weapon systems characteristic of the troops of the Order, the squads of Russian princes and the militias of the Baltic peoples. Thus, readers will be able to imagine what the warriors of the first half of the 13th century looked like. in various parts of Europe, Rus' and the Baltic region. The book is richly illustrated, equipped with scientific equipment and is of interest both to professional historians and museum staff, and to a wide range of readers.