Following the Battle of Britain, Germany regrouped and turned its attention to other fronts. Greece, Yugoslavia, North Africa, and eventually Russia would all be invaded in 1941. The Luftwaffe was dispersed throughout several theaters and only a few fighter Gruppen remained to defend the Channel. Meanwhile, Fighter Command expanded as rapidly as it could, and in the spring of 1941 switched its mission from defense to deliberate war of attrition against the Luftwaffe in France. Initally, large fighter sweeps were tried and some major battles occurred, but the Germans soon learned to ignore the sweeps. To draw them out, the RAF started flying "Circus" missions in which small groups of bombers, heavily escorted by Spitfires, attacked targets in France. The Germans could not ignore the bombers. By this time, the Spitfire Mk. IIA was in service and showed some superiority over the late-model Bf 109Es, but the new Bf 109Fs had also appeared to equalize things.
