Battle of Britain's 75th Anniversary 2015
The Dunkirk evacuation, code-named Operation Dynamo, also known as the Miracle of Dunkirk, was the evacuation of 33.000 Allied soldiers from the beaches and harbour of Dunkirk, France, between 27 May and 4 June 1940.After the fall of France at the end of June 1940, Nazi Germany had one major enemy left in Western Europe -- Great Britain. Over confident and with little planning, Germany expected to quickly conquer Great Britain by first gaining domination over airspace and then later sending in ground troops across the English Channel (Operation Sealion).
Battle of Britain (1940): The Battle of Britain was the intense air battle between the Germans and the British over Great Britain's airspace from July 1940 to May 1941, with the heaviest fighting being from July 10th to 31st  October 1940. Winston Churchill the Prime Minister said in Parliament “The Battle of France is over. I expect that the Battle of Britain is about to begin. Upon this battle depends the survival of Christian civilization? Upon it depends our own British life, and the long continuity of our institutions and our Empire. The whole fury and might of the enemy must very soon be turned on us. Hitler knows that he will have to break us in this Island or lose the war. If we can stand up to him, all Europe may be free and the life of the world may move forward into broad, sunlit uplands. But if we fail, then the whole world, including the United States, including all that we have known and cared for, will sink into the abyss of a new Dark Age made more sinister, and perhaps more protracted, by the lights of perverted science. Let us therefore brace ourselves to our duties, and so bear ourselves that, if the British Empire and its Commonwealth last for a thousand years, men will still say,the first
first time the Germans had faced defeat in World War II.
The Battle of Britain -A  Full Length Documentary
just click on the center of the screen to watch the videoalso  in the right hand corner of each you can click on full screen
Also it must be remembered that Bomber Command  also during this time were bombing sites and airfield in France and Belgium and Germany and though out the war of which 55,000 of Bomber Commands service personnel also paid the ultimate sacrifice.
This also gave the Army a breathing space and a chance to regroup and re-equip the survivors from  Dunkirk  the National Service men & women , and the other nations who joined then joined  us in the Normandy landings (codenamed Operation Neptune) were the landing operations on 6 June 1944 (termed D-Day) of the Allied invasion of Normandy
FINALLY let us not forget the civilian population of men and women who suffered in the blitz ,Mainly London with  57 Continuous days of bombing  but also many other industrial towns such as Coventry Birmingham  Manchester and Liverpool to name a few and  most of the large Ports But they  carried on  Day and Night, in our factories, in the mines and on the land , not forgetting the Police ,the Fire Brigade and our Hospitals everybody played a part.
The  Rationing of food and clothing  lasted for 14 years and ended on July 4, 1954. 

                                                                                                        
But what if we had lost the Battle of Britain???

A lot of the British people borne in the late 60’s onwards do not realize the sacrifices and hardship their grandparents had to suffer including rationing of food & clothing.  But if we had lost it would have been far worse read on :-
Historian and Author Len Deighton summed it up as well as anyone “Had the Luftwaffe eliminated Fighter Command, its bombers could have knocked out all the other dangers one by one. Given the sort of command of that the Luftwaffe had achieved in Poland in only three days, German bombers guided by radio beams, could have destroyed everything from Whitehall to the units of the Home fleet. There would have been no insurmountable problems for their invasion fleets and airborne units if the air was entirely German controlled.
The following article was published in a Special edition of   “Bygones” in the Nottingham Post on Saturday 4th September 2010 during the 70th Anniversary of the Battle of Britain.  A transcript of the speech in Life Magazine during 1940. Reich Marshal Richard Darre   explained that before autumn they shall be the absolute masters of two continents ... a new aristocracy of German masters will be created with slaves assigned to it, these slaves to be their property and to consist of landless, on-German nationals.... we actually have in mind a modern form of medieval slavery which we must and will introduce because we urgently need it.  As soon as we beat England we shall make an end of you Englishmen once and for all. Able-bodied men and women between the ages of 16 and 45 will be exported as slaves to the Continent. The old and weak will be exterminated. All men remaining in Britain as slaves will be sterilized; a million or two of the young women of the Nordic type will be segregated in a number of stud farms where, with the assistance of picked German sires, during a period of 10 or 12 years, they will produce annually a series of Nordic infants to be brought up in every way as Germans. These infants will form the future population of Britain. They will be partially educated in Germany and only those who fully satisfy the Nazi's requirements will be allowed to return to Britain and take up permanent residence. The rest will be sterilized and sent to join slave gangs in Germany. Thus, in a generation or two, the British will disappear.
The official figure for the number of Jews in Britain was 300,000, but Germany believed the actual Jewish population to be much larger.  A distinction was made between refugee Jews (those who had recently fled the Continent) and native Jews; the former were to be rounded up first. Ultimately, audiences are assured, all Jews would have been shipped to the Continent and killed enmass as part of the “Final Solution.”
The Battle of Britain 1940
“THIS WAS THEIR FINEST HOUR “Churchill aptly described the aircrew who fought in the battle as "The Few” These were 2353 young men from Great Britain, with 574 from overseas. 544 lost their lives during the battle, and nearly 800 more died before the end of the Second World War.
But let’s also remember the “Many” The RAF Personnel working day and night, keeping the aircraft serviceable and running all the supporting services needed to keep them flying often though air raids. Although the Germans continued to bomb Great Britain for months, by October 1940 it was clear that the British had won and that the Germans were forced to indefinitely postpone their sea invasion. The Battle of Britain was a decisive victory for the British, and which was the first time that Hitler had faced a defeat
Winston Churchill said in Parliament   “Never in the field of human conflict was so much owed by so many to so few. All hearts go out to the fighter pilots, whose brilliant actions we see with our own eyes day after  day, but we must never forget that all the time, night after night, month after month, our bomber squadrons travel far into Germany, find their targets in the darkness by the highest navigational skill, aim their attacks, often under the heaviest fire, often with serious loss, with deliberate, careful discrimination, and inflict shattering blows upon the whole of the technical and war-making structure of the Nazi power. On no part of the Royal Air Force does the weight of the war fall more heavily than on the daylight bombers who will play an invaluable part in the case of invasion and whose unflinching zeal it has been necessary in the meanwhile on numerous occasions to restrain”….