This book describes in detail the military-political situation in the Baltic region, the activities of military monastic orders, the Mongol invasion of Russia and the countries of Western Europe. The reader will get acquainted 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, made an attempt, on the basis of most of the well-known pictorial and archaeological sources, to reconstruct the appearance of the participants in the battle, to present various options for defensive and offensive weapons complexes characteristic of the troops of the Order, squads of Russian princes and militias of the Baltic peoples