During the years 1939 -1940 Finland was engaged in the Winter War and the Continuation War against the Soviet Union. The Finnish Air Force had to fight against a massively superior force from the very outset of the Winter War on the 30th November 1939. In the first two days of that war more than 10 enemy aircraft were shot down. In spite of the opponent's overwhelming superiority of numbers the Finnish Air Force managed to achieve many victories until the Soviet Union sent large reinforcements to the front, equipped with more technically advanced aircraft. This advantage enabled them to obtain air supremacy towards the final stage of the war. When the Continuation War broke out in Spring 1941, the Finnish Air Force was more effective because of better equipment and additional personnel which resulted in air supremacy being achived on all sectors of the front. It was not until the expensive offensive by the enemy which began in June 1944 that the Soviet Union gained air supremacy through their overwhelming resources which eventually faltered because of effective defence tactics and counter-attack measures.