In the year 1923 the Soviet air force came properly into existence. While the Soviet Union had air squadrons before this, and while each squadron would remain under the authority of its local ground commander, all air units began reporting to a Chief Directorate of the Air Force of the Red Army. By 1928, after continued military re-organization, complete control of the Soviet air force fell to this Directorate.
Before World War II, the Soviet Union sent aircraft and other aid to the Republican side of the Spanish civil war. Between October, 1936 and December, 1948 they supplied 1,409 soviet aircraft – mostly I-15 and I-16 Polikarpovs – along with pilots and instructors. These planes were outclassed by the Messerschmitt Bf-109’s used by the German-supported Nationalists and so 1,176 of the soviet aircraft were destroyed in battle. Seventeen Soviet pilots were deemed Heroes of the Soviet Union for their conduct in the civil war.
Soviet losses in the Spanish civil war led them to focus more on developing ground-attack and close support airframes. This doctrine is best exemplified by the famous Il-2 Shturmovik, a low-altitude, heavily armed and armoured tankbuster soviet aircraft dubbed Der Schwarze Tod (The Black Death) by German forces.
In July of 1940, under a year before Germany attacked, the Soviet Union began a further re-organization of its forces. Squadrons that formerly had 20-30 planes were put together to form 60 plane regiments. Three to five of these regiments formed an air division. Along with this change was it was planned to upgrade existing planes in the force to their newest models. Progress was slow with the re-organization and the upgrades however, and by June 22, 1941 when Germany invaded, the process was only 20% completed.