The paper examines the influence of the natural factor on the military history of Russia. It is natural conditions that determined the choice of military strategy and tactics, the state of the system and supply of troops, and to a large extent - and the results of combat operations. The major part of the territory in the south of the country (1250 km from Voronezh to Ordzhonikidze, from north to south and 1,000 km from Taman to Astrakhan from west to east) was turned into a combat zone from the summer of 1942 to the autumn of 1943. It is characterized by various forms of relief (from the plains and lowlands to highlands), climatic zones (from temperate continental to subtropical) and native zones (from the steppes to the semi-desert and glaciers). Various natural conditions had different effects on the course of military operations. Analyzing combatant operations in the south of the country it became evident that the Soviet military commanders didn’t always take into account the influence of natural factors. Hundreds of thousands of ordinary soldiers and commanding officers with much effort and loss of their lives had to correct the errors of the military commanders in order to improve the situation. Only after the radical turn in the Great Patriotic War, the Soviet tactics underwent major changes. For instance, when planning offensive and defensive operations, one took into account natural factors. In particular, terrain models were studied to present the features of the upcoming battles in detail. This was one of the most important conditions for the victory, the beginning of which was laid in the battles of 1942-1943 in the south.