In the 1920s and 1930s, the Red Army underwent intensive development, both in terms of increasing its number of jobs and saturation with technical weapons. In addition to the very intensively developed artillery, considerable emphasis was also placed on the introduction in the 1930s of new models of mortars, which were perceived as cheap to produce, easy to use and effective infantry support weapons. At that time, mainly two models of the 82 mm caliber mortar were introduced - 82-PM-36 and 82-PM-37, which were structurally quite clearly based on the French Brandt Mle 27/31 mortar. In 1941, a modified version of the two previous mortars, designated 82-PM-41, was introduced at the battalion level. It kept many of the positives of the 82-PM-37 mortar, but was much easier to transport, lighter and cheaper to produce. It is worth noting that since 1939, the 120-PM-39 mortar with a caliber of 120 mm was produced, which was also based on the French mortar - Brandt de 120 mm Models 1935. It was a much heavier weapon, with a larger mass of the projectile fired, and therefore it was divided at the regiment level, more rarely at the battalion level. It is worth noting that in 1941 a total of 66 mortars of various calibers were employed by the Soviet rifle division. In the course of World War II, the role of mortars in the Red Army increased even more. New weapon models were also introduced - including the successful 120-PM-43 caliber 120 mm. In 1945, there was already a mortar regiment in the position of an infantry division.