Operation Sealion, the German Invasion of Britain 1940.
"The German Paratroops jumped at dawn, as they had done in Holland, in Belgium, in Norway. But this time there were more of them. Nearly 8000 Fallschirmjager of the 7th Fliegerdivision, carried by a stream of 600 Junkers 52 transports.
The time was 6 o'clock on the morning of September 22nd 1940, just a few minutes after the official sunrise on a grey cloudy, windless day.
Below the long lines of aircraft the unwontedly calm sea was dark with the countless barges and motorboats of the invasion fleet. By breakfastime close on 90,000 troops were successfully ashore on the beaches between Folkestone and Seaford. Operation Sealion had begun."
Excerpt from Sealion by Richard Cox.
By June 1940, less than a year after the start of the war, the German Army had overrun France, Poland, Holland, Belgium, Denmark and Norway. The beaten British Army had withdrawn from Dunkirk without its heavy weapons and equipment. Britain now stood alone against a German dominated Europe, with only 25 miles of the English Channel separating it from the victorious German armies.
Britain was very weak, but still had a strong airforce and navy. Germany expected Britain to surrender, but although isolated it did not surrender. On June 4th the new Prime Minister Winston Churchill made his now famous "... we shall fight them on the beaches..." speech.
Germany had two options, to besiege to Britain or to invade it.
On 16th July 1940 Hitler issued his Directive 16 "...I have decided to begin to prepare for, and if necessary to carry out an invasion of England.." The operation was given the codeword Sealion.
The German Navy was reluctant to attempt an invasion. It was inexperienced in amphibious warfare, its navy was weak and it knew full well how powerful the Royal Navy was. However, the Army was keener and plans were hastily drawn up. It was possible that Hitler was bluffing, but realised that full scale preparations were needed to convince the British to either come to terms or surrender.
The German Invasion Plans.
The Army wanted to land on a 200 mile wide front stretching from Lyme Regis in the west to Ramsgate in the east, however the Navy was constantly worried about the threat from the Royal Navy insisted on a narrower landing. A compromise was arrived at where the landings would be from Brighton in the west to Folkestone in the east. The first wave of about 60,000 men was to secure the beaches while the second wave comprised of the tank divisions that were to break out of the beachheads and capture the secondary objectives. The landings were to be assisted by airborne troops landing on the Downs above Brighton and north-west of Folkestone to help with the capture of crossings over the Royal Military Canal.
The British Defences.
In Britain defences were hastily erected. On 14th May 1940 the Local Defence Volunteers were formed. It was made up of men too old, or too infirm to join the regular army. The LDV later became known as the Home Guard after Churchill used the phrase in a radio broadcast.
General Sir Edmund Ironside was put in charge of Britain's defence. With the lack of equipment he decided to build a static system of defences which could delay the Germans long enough for more mobile forces to counter attack. The defences were made up of concrete pillboxes , anti-tank obstacles, trenches and minefields which took advantage of natural and man made features. The main line of these defences was known as the GHQ Stop Line. In July 1940 General Ironside was replaced as commander of the Home Forces by General Alan Brooke. General Brooke changed the defence strategy away from static defence lines to mobile formations, although defence lines continued to be built.
The Germans Attack.
For the invasion to succeed the Germans had to defeat the Royal Air Force. The air offensive began on 12th August. At first the Germans concentrated on the radar stations and airfields of the RAF. Unknown to the Germans these tactics soon had the RAF almost on its knees. However, the Germans changed tactics and started bombing London and the aircraft factories, thereby allowing the RAF to regroup. Legend has it that the German decision to bomb London was caused by RAF raids on Berlin, which in turn was caused by a German bomber crew losing their way and accidentally releasing their load over London.
Codeword Cromwell - Invasion Imminent.
In the first week of September reconnaissance of the Channel ports -Ostend, Le Havre, Flushing, Ostend, Dunkirk and Calais- had shown a substantial build-up of barges. At Ostend alone 280 had arrived during the previous week. Substantial numbers of motor-boats and larger vessels had also moved down the coast to the same area. Considerable numbers of bombers had just moved to airfields in the Low Countries and dive-bombers appeared to be assembling near the Straits of Dover. The moon and tide favoured a landing between September 8th and 10th. Everything pointed to an invasion. At 5.20 p.m on 7th September the Chiefs of Staff met. At 8.07 p.m. they decided to bring Home Forces to a state of "immediate readiness" and issued the word “Cromwell” meaning invasion imminent.
8pm on a Saturday night was not a good time to raise an alarm. Most duty officers at military commands were junior officers, who in the main had not been briefed fully on procedures. Many thought the signal meant an invasion had already begun. All over the country coastal artillery sites were manned, thousands of units put on steel helmets and waited for first sight of the enemy. Home Guard units were mobilised and manned their pillboxes and their improvised defences. The Beetle invasion warning network, just completed days earlier on August 26th, crackled into life and Operation Banquet was initiated whereby all flyable training aircraft that weren’t fighters were converted into bombers. Police rounded up trainee pilots, some barely able to fly, from pubs, dance halls and cinemas and as they reported back to their airfields they were shocked to see bombs being loaded onto their flimsy training aircraft. More than half of Bomber Command's medium bombers stood by to support Home Forces. Some Home Guard Captains sounded church bells, which they were only supposed to do on their own initiative if they actually saw more than 25 of the enemy, and other units, both Home Guard and the regular Army, thought the bells were confirmation of enemy troops in the area. Several East Anglian bridges were blown up by the Royal Engineers and there were more serious consequences when three Guards officers were killed in Lincolnshire when their vehicle went over a newly laid mine as they rushed back to their unit. As daylight dawned on the 8th it was clear that Sealion had not been launched and gradually senior officers managed to restore sanity to the situation
Indecision and Postponement.
With the failure of the German Air Force to defeat the Royal Air Force the German High Command became increasingly nervous about the chances of a successful invasion. Initally it was intended to invade in August but on 3rd September the High Command postponed Sealion to the 21st and then the 27th which would be the last time that year the tides would be suitable.
On 15th September the German Air Force launched a major attack to destroy the RAF. The Germans lost twice as many planes as the RAF. This signalled the end for Sealion. Hitler had it postponed indefinitely, while his attention was drawn towards the Soviet Union.
There a two schools of thought on how successful a German Invasion would have been had the RAF been defeated.
The first is that a German invasion, even with air superiority would have probably failed. In 1974 a wargame was played at the Royal Military Academy Sandhurst. The wargame involved a number of senior military men from both sides including Adolf Galland the famous Luftwaffe fighter ace and Air Chief Marshal Sir Christopher Foxley-Norris. It presumed that the Luftwaffe has not yet won air supremacy and utilised previously unpublished Admiralty weather records for September 1940.
Even without air supremacy the Germans were able to establish a beachhead in England using a minefield screen in the English Channel to protect the initial landings from the Royal Navy. However, after a few days, the Royal Navy was able to cut off supplies from the German beachhead, isolating them and forcing their surrender.
The second is that , with the Luftwaffe dominating british skies, they would have been able to target oil refineries, industry and ports relatively unimpeded. Combined with a blockade by U-Boats Britain would have been starved either into surrender or a negotiated peace with Nazi Germany.
What Might Have been...
"Later that afternoon with the Germans already in Trafalgar Square and advancing down Whitehall to take their position in the rear, the enemy unit advancing across St. James 'Park made their final charge. Several of those in the Downing Street position were already dead... and at last the Bren ceased its chatter, its last magazine emptied.
Churchill reluctantly abandoned the machine-gun, drew his pistol and with great satisfaction, for it was a notoriously inaccurate weapon, shot dead the first German to reach the foot of the steps. As two more rushed forward, covered by a third in the distance, Winston Churchill moved out of the shelter of the sandbags, as if personally to bar the way up Downing Street. A German NCO, running up to find the cause of the unexpected hold-up, recognised him and shouted to the soldiers not to shoot, but he was too late. A burst of bullets from a machine-carbine caught the Prime Minister in the chest. He died instantly, his back to Downing Street, his face toward the enemy, his pistol still in his hand."
Excerpt from If Britain Had Fallen by Norman Longmate.