The Battle of Britain was so named by Winston Churchill, barely a month after he took office as Prime Minister of Great Britain in May 1940. The might of Nazi Blitzkrieg tactics had rolled over mainland Europe and Hitler stood on the coast of France looking at a tiny island just twenty miles away.
The British Empire and Commonwealth - the largest the world had ever seen - looked under-prepared and vulnerable. Before German forces could invade, Hitler needed to ensure that they controlled the skies. His Luftwaffe commander, Reichsmarschall Göring, assured him it would take only four weeks.
The Battle of Britain was fought over the summer of 1940 in three phases as the Luftwaffe probed and challenged the English defences.
The first phase, beginning in July, sought to destroy shipping, coastal defences and the British 'secret weapon' - the radar stations on the coast which gave vital forewarning of Nazi raids.
The second concentrated on the airfields from which the RAF mounted their increasingly desperate defence.
The third phase became infamous as 'The Blitz' where Hitler turned the destructive force of his bombers onto the people of London, targeting key strategic areas such as the East End ports, aircraft and vowing to intimidate the City.