The Soviet Air Force fought in the Spanish Civil War as did many Luftwaffe pilots as a prelude to what was to come. In 1939 Russia fought the Winter War against Finland and lost over 700 aircraft. In June 1941 Germany invaded Russia and the Luftwaffe destroyed over 1400 Soviet aircraft on the ground the first day and over 4,000 in the first few days. The Soviet air force survived these losses and with the development of new aircraft like the YAK 7 were able to virtually destroyed the German air force in the east during the balance if the war.