The Battle of Britain can be seen as a significant turning point in the war against Germany as they are unsuccessful in their bid to capture the British Isles. However, it can also be said that this battle's only real importance was the fact that Britain survived the attack, as the Allies were unable to retake Europe and defeat Germany at this point. Yet before the Battle of Britain Germany is the only victorious side.
When war was declared in 1939 and Hitler had ordered the invasion of Poland the Allies were unable to stop him, and with the Red army (the Russians) invading Poland from the East, as planned for in the Nazi-Soviet pact, the country was taken within a matter of weeks. In the aftermath of the Polish defeat the French and British armies prepared for an extended struggle with Germany, who now planned for an Offensive on the Western front - the Battle of France.
The Allied troops were in no way prepared for the modern, high speed tactics (at the beginning of the war) that the Germans would deploy, as they were only prepared to fight in the style of the of the Great War of 1914 - trench warfare and slow strategic advances. Hence such quick victories for the Germans and the rapid fall of France in 1940. With the Battle of France over Hitler now sought to invade Britain.
In the summer of 1940, the German Luftwaffe attempted to win dominance over southern Britain and the English Channel by destroying the Royal Air Force and the British aircraft industry, as victory over the RAF was seen by the Germans as absolutely essential if they were to eventually mount an invasion of the British Isles. In view of the strength of the Royal Navy,