Germany did not lose the Battle of Britain

[Avimimus]

I actually think it was a major turning point in the war.

The simple fact is that the German airforce suffered heavily during the whole of 1939 and 1940 with almost even attrition rates against inferior opponents. But, if Germany had managed to get England to make peace in '39 and had avoided bombing cities then it could have been a victory. It could even have one them the war.

But the failure of fascist sypathisers to consolidate power in the parliament, the failure to demoralise or destroy the RAF and the bombing of civilian targets prevented this. It was the greatest political (not necessarily military) defeat imaginable.

With England still in the war and the Commonwealth behind her and with the pro-fascist element relatively restricted in what they could do made German defeat inevitable (even if the United States stayed isolationist - which became less likely each day the U.K. held out).

After this point only a really major alteration to history like a fascist coupe in an allied country, a German attack on the Soviet Union in 1938-1939 (which the allies would have been sympathetic to), a giant U-boat fleet or a much stronger German air defense could have altered events.

Eventually, even if it took an extra year, the Great Patriotic War would end in Berlin.