1. A NEW ARMADA WAS PLANNED
Picture the historic moment. France had fallen to the Nazis. The terrifying Dunkirk evacuation had happened - a victory in defeat, yes, but a sign of just how unstoppable Hitler's forces seemed to be. And the Fuhrer was set on taking his European conquest across the channel. "As England, in spite of the hopelessness of her military position, has so far shown herself unwilling to come to any compromise," Hitler said, "I have decided to begin to prepare for, and if necessary to carry out, an invasion of England."
The plan was called Operation Sea Lion, an epic assault which would have involved multiple waves of invaders making their way across the waters on an armada of boats, to land on the coastline from Ramsgate in the east to Dorset in the west. Some of the Nazis' military bigwigs thought it would fail, but others were more complacent, dubbing it a mere "river crossing".
2. BLENHEIM PALACE WAS A SPECIFIC TARGET
One of our country's grandest residences was firmly in Hitler's sights. Not for destruction, but for habitation. The luxurious Blenheim Palace, which is a picture-postcard example of the English stately home, was intended to become Hitler's own home after a successful invasion. This may have had something to do with the fact it was the family home of Winston Churchill, who had in fact been born there. Hitler would no doubt have relished basking in a place so cherished by his nemesis.
3. DEATH SQUADS WOULD HAVE BEEN DEPLOYED
In mainland Europe, the Holocaust took many forms. The camps were one manifestation of Nazi horror, but death was also dealt out by the Einsatzgruppen. These were roving squads of gun-toting mass murderers, who would wipe out whole swathes of civilians on the Eastern Front. The intention was for new Einsatzgruppen to be sent across the British Isles to round up subversives - from Jews to intellectuals.
A list known as the "Black Book" was drawn up, listing some of the most prominent cultural and political figures in the UK. They included names like writers HG Wells and Aldous Huxley, as well as future prime minister Clement Attlee. Being on the list would later be a source of pride and amusement for some, with Noel Coward saying: "If anyone had told me at that time that I was high up on the Nazi black list I should have laughed and told them not to talk nonsense".
4. CIVILIANS WERE SET FOR SLAVE LABOUR
It's a common misconception that the Nazis would have somehow treated the population of Britain with more sympathy and respect than civilians in mainland Europe. While there may have been less of the visceral contempt they had for Jews and Russians, Hitler's top brass had brutal plans in place for Britons. Specifically, British men. If the invasion had succeeded, all healthy men from their teens to their mid-40s would have been eligible for being rounded up and sent across the channel to work in punishing slave labour camps and factories. Somehow, the Nazis would then have had to prop up the stricken economy and infrastructure of an abruptly-depleted Britain - perhaps by putting more women into work.
5. THE MONARCHY WOULD HAVE TRANSFORMED
The Nazis wouldn't have overthrown the British monarchy, but they would have deposed the ruler in favour of Edward VIII - the man who'd been forced to abdicate the throne a few years earlier in order to be with his beloved Wallis Simpson. The couple had long been regarded as potential allies of Hitler, and had in fact visited the Fuhrer before the war. There was a daring Nazi plan to locate and detain the former king and his wife, with a view to installing Edward as the monarch in a new, Nazified Britain.
6. BLACKPOOL WOULD HAVE STAYED... BLACKPOOL
While much of Britain would have been left devastated after an invasion, and atrocities would have been inevitable, one place would likely have been left unscathed: Blackpool. It seems the Nazis had their eyes on the resort town, and wanted to spare it from attacks so it could serve as a place for weary German soldiers to rest and recuperate by the sea. The sight of the swastika flapping from the top of the tower would have probably been the only major change.