At the outset of World War II, the Luftwaffe was one of the most modern, powerful, and experienced air forces in the world, dominating the skies over Europe. In 1940, the Luftwaffe lost the Battle of Britain over the skies of England, the first all-air battle. Following the military failures on the Eastern Front, from 1942 onwards, the Luftwaffe went into a steady, gradual decline that saw it outnumbered and overwhelmed by the sheer number of Allied aircraft being deployed against it.