In the summer of 1940 Churchill and his Chiefs of Staff expected an airborne invasion and a seaborne one, most likely on the east coast where the beaches were flatter and the terrain likewise making it easier country for motorised troops. They thought it much less likely that there would be an invasion across the Channel.
If this was in fact the case, they were completely wrong. However, Peter Fleming’s Invasion 1940 was written in 1957 and necessarily has one omission: he cannot mention Bletchley and its contribution. On the other hand he does tell of the successful German decryption of British naval ciphers until the late summer of 1940.
Meanwhile in Germany Hitler failed to implement Operation Sea Lion. He had two reasons to be cautious. First he over-estimated the strength of the opposition he would encounter. Although the Home Guard were a million strong they were ill-equipped and scattered over England, Scotland, Wales and Northern Ireland. Likewise the army, navy and air force were stretched and under-equipped in the face of demand for reinforcements in such theatres as North Africa and Singapore.
Secondly, he was content to delay an invasion as he believed that England would capitulate and invasion should be a last resort. He attempted to undermine morale by making broadcasts in English, supposedly originating in England, counselling surrender. Leaflets were dropped and on the night of 13/14 August German aircraft dropped a number of things (like wireless transmitters, explosives, maps, instructions to imaginary agents, etc) over the Midlands and the Lowlands of Scotland to give the impression of an imminent invasion supported by a Fifth Column. This material also pointed to an invasion on the east coast. Finally the scale of bombing raids was stepped-up and directed at London to destroy morale.
Hitler did not in fact have any Fifth Column and attempts to infiltrate spies were thwarted. Some of these seem comical now but had deadly intent. “Dr Herman Goertz, a lieutenant on the reserve of the Luftwaffe, was dropped by parachute in Co Meath on the night of 5/6 May. He was fifty years old and in 1936 had been sentenced to four years’ imprisonment for spying, conscientiously but not very usefully, on RAF airfields.”
In Maidstone prison he met members of the IRA and his mission was to prepare for a German invasion of Ireland. Everything went wrong. He was dropped in the wrong place wearing German uniform but failed to recover his parachute, wireless and other equipment. He should have been in Co Wicklow some seventy miles away. He afterwards wrote:
“I swam the River Boyne with great difficulty since the weight of my fur combination exhausted me. This swim also cost me the loss of my invisible ink.” He discarded his uniform. “I was now in high boots, breeches and jumper, with a little black beret on my head … I kept my military cap as a vessel for drinks and my war medals for sentimental reasons … I had no Irish money and did not realise that I could use English money.” Surprisingly he was not arrested until November 1941 by which time although he had made wireless contact with Germany he achieved nothing. Fleming sums up the incident.
“The lonely, brave, baffled figure trudging across the empty Irish landscape in jackboots, with a little black beret on his head and a pocket full of 1914-1918 medals, is a reminder of how far the German intelligence effort fell short of those standards of subtlety and dissimulation which were expected of it.”
In the early hours of 3rd September 1940, four German agents were sent to the south coast in a fishing boat escorted by two minesweepers. The first pair landed near Hythe and were arrested by 5.30 am, hampered by having very little grasp of English. The other pair landed at Dungeness. One who spoke good English gave himself away by trying to buy cider at breakfast time. His companion was not caught until the following day. Three of these men were hanged in Pentonville Prison the following month. One, a Dutchman, was acquitted as he had been blackmailed into taking part in this ill-planned mission.
Operation Sea Lion was first planned for mid-August but was delayed as operational problems were encountered until it was abandoned in mid-September. Germany’s failure to control the air or the sea posed too great a risk. Peter Fleming poses the question: “were there any circumstances in which, during the summer of 1940, Hitler could have successfully attempted the invasion of England?” Here is part of his answer.
“Had the Germans been able to put quite a small force – say three or four divisions – across the Channel early in June (that “very dark hour”, as Churchill called it two months later) they might have done the trick. The reinforcement, and indeed the maintenance, of this force would have presented serious difficulties, but some of these could have been overcome by the capture of airfields in south-east England, which in those days would not have been a hard task.”
Invasion 1940 examines that fateful summer in much greater detail and is well worth reading. Although I have not read it, I suspect that Charles Graves’s The Home Guard of Britain, published in 1943, throws more light on this period and is rich in anecdotes.