Operation Sealion – Hitler’s planned invasion of Britain

On 19th May 1940, Winston Churchill made his first broadcast as Prime Minister. With defeat in France imminent and speaking just seven days before the start of the Dunkirk evacuation, he invoked the threat of Nazi invasion in Biblical terms. Churchill urged Britons: ‘Arm yourselves, and be ye men of valour, and be in readiness for the conflict, for it is better for us to die in battle than to look upon the outrage of our nation and our altar”.

Much history and more fiction has been written about Operation Sealion - the proposed Nazi landings on the South Coast with Bexhill as its nexus. In hindsight, few historians think it was ever a realistic possibility. In a hurry to destroy Russia, Adolf Hitler had expected London to sign a quick armistice in exchange for the Royal Navy's freedom of the seas and the preservation of the British Empire.

Behind him, Hitler’s naval commanders doubted they could meet the challenges of supplying a cross-channel assault. His air force thought they could break British resistance on its own. His army over-simplified the realities of a combined amphibious & airborne invasion. They all reasoned that British fear of invasion alone might be enough to force a peace deal.

Winston Churchill
Winston Churchill (Wikimedia Commons)

Churchill’s genius was to turn that vague threat into a rallying call to arms. The long months of the so-called Phoney War and the rapid collapse of France had confounded the country and sapped morale. But invasion was a readily understandable threat that, wrapped in Churchill’s peerless oratory, galvanised the nation exactly as he intended. The American journalist Ed Murrow was one of many impressed by the effect of Churchill’s call, telling his US listeners: “To me it seems that this country is ten years younger than it was ten days ago.”

In fact historian Michael Glover is one of many post-war experts who concluded that the threat was never a realistic one. Britons, he wrote, armed themselves in 1940 to combat a menace that did not exist, to give themselves the courage to face a war which “on any logical premises, they had no hope of winning”.

Hitler continued to make vague threats to invade Britain ‘if necessary’ in the weeks after Dunkirk. His directive on 16 July 1940 read: “As England, in spite of the hopelessness of her military position, has so far shown herself unwilling to come to any compromise, I have therefore decided to begin to prepare for, and if necessary to carry out, an invasion of England.”

And those preparations were intensive. By August 1940 the German Navy had secured a landing force of 1,900 barges, 168 merchant ships, 386 tugs & trawlers, and 1,600 motor boats to get four divisions across the Channel on ’S-Day’, and five more in the two days following - in theory.

A rare photo of German invasion barges exercising near the captured French port of St Malo (©IWM HU95927).
German invasion barges exercising near the captured French port of St Malo (IWM HU95927).

The invaders would come in river barges fitted with rudimentary landing ramps, so prone to swamping they had to be limited to specific tides and moonlight levels. That meant S-Day would have to have fallen between 20-26 August, or between 19-26 September 1940. Any later would risk the effects of bad weather, and with the invasion of Russia secretly being planned for 1941, a delay to the following spring was ruled out.

The German historian Peter Schenk has made the closest study of the surviving battle plans, including the landing of General Erich von Manstein's 38th Army Corps between Bexhill and Eastbourne in 1940. Two divisions out of an initial force of nine, Manstein's invaders of 1940 planned to board at Boulogne - as Julius Caesar had when invading England in 55 BCE, and land at Pevensey, as William the Conqueror did in 1066.

The first, the 34th Division, planned to land on S-Day from Cooden Beach across the Pevensey Sluice, and up to the east bank of Waller’s Haven. Its 107th and 80th infantry regiments would attack under cover of smoke in rubber boats and small motor launches, prepared to face 20 British gun emplacements, double rows of concrete ‘Dragons’s Teeth’ tank traps, barbed wire and landmines.

A typical German infantry division such as the 34th would normally be comprised of six regiments, about 3,200 men each, 19,200 men in total, along with 1,650 cars and lorries, a thousand motorbikes, 40 tanks, 75 anti-tank guns, 40 howitzers, and 125 mortars. Surprisingly perhaps, the division would also bring 2,000 pedal bikes and more than 4,000 horses, mainly to shift the artillery.

Manstein's second German division, the 26th, would land between Langney Point and west of Pevensey. Both divisions were to be supported by special forces from the Brandenburg Regiment, who would wear captured British Army battledress over their German tunics, speak English and ride captured British motorbikes. They aimed to sow confusion and havoc behind the British lines.

Amphibious German tanks developed for the invasion of England.
The German Tauchpanzer III (‘Diving Tank’) was an up-gunned version of the Mark III panzer, then the main battle tank of the German Army, as developed for the invasion. It was fitted out with pipework and sealant to allow it to run underwater for up to 20 minutes in waters up to 15 metres deep, ready to emerge from the seas to support their troops on the beach and beyond. The picture shows one of the tanks being tested by the German Navy on the North Sea coast (IWM HU7652).

Forty tanks were assigned to support the 34th Division’s three pronged first day's attack, a left flank advance past Wartling to Windmill Hill, a central thrust past Hooe to north of Ninfield, and a right flank attack up to Lunsford’s Cross that would then turn right and south to attack Bexhill from behind through Sidley.

There the troops would link up with elements of the 1st Mountain Division, due to land at Combe Haven to the east. The initial invasion overall called for 173,000 men and historian Geoff Hewitt has estimated that even with minimal resistance from the Royal Navy, the Germans would have needed eleven days for their own Navy to bring over all of them and their kit. Speed would be of the essence.

General Erich von Manstein
Erich von Manstein (Bundesarchiv H01757)

But the commander of the attack on Bexhill was a master of tactical speed. 38th Army Corps General Erich von Manstein was the author of the strategy that split the Allies in May 1940 with a surprise attack through the Belgian Ardennes. His own peers, and the British soldier-historian Basil Liddell Hart, regarded him as the German Army’s most able battlefield strategist. During the invasion of France Manstein had won the Knights’  Cross, Germany’s highest military award, for leading his 38th Corps in a 400 kilometre race from the Somme to the Loire river in just 14 days. The equivalent act after S-Day would have been a two week fighting advance from Bexhill’s promenade to the steps of York Minster.

According to his biographer Benoît Lemay, Manstein was a keen advocate of Operation Sealion, and strongly believed it would work. Manstein’s priority was to quickly secure his beachhead up to a line from Heathfield to Lewes, gather the rest of his men and then strike north. The 38th Corps' 26th Division was to capture Beachy Head but bypass Eastbourne. Bexhill however would have marked a crucial communications point on the line dividing the two main German invasion armies, in the dead centre of the two landing zones. Manstein might have simply raced by Bexhill but his assignment of a regiment to loop south at Lunsford’s Cross and back towards to the town strongly suggests he intended to capture and hold it.

Advance plans for the Nazi attack on Bexhill
General Erich von Manstein's attack plan for day one of the proposed Nazi invasion of England in 1940. Map details drawn from research by Peter Schenk, designed by Ashley James.

In truth both sides thought the operation beyond the existing resources of the German military. In his Memoirs of WWII, Churchill concluded that the Germans “had neither the tools or the training” to pull off the invasion in the face of British sea and air power. Intriguingly, he added: “There were indeed some who on purely technical grounds, and for the sake of the effect the total defeat of his expedition would have on the general war, were quite content to see him try."

But by mid-September 1940, with another set of landing-friendly coastal tides missed, the demands of the planned invasion of Russia pressing on the military, and above all, the failure to defeat the RAF in the Battle of Britain, it was clear to Hitler that the moment to invade England - assuming that he ever seriously considered it - had passed.

Operation Sealion became one of the great non-events of history. But as Michael Glover adds, it was and remains a British victory. Britons convinced themselves, and most of the world, that they had faced down the Nazi military machine, he wrote. “Hitler faced his first defeat, and a very serious one, when on 17 September 1940 he approved the order: Sealion: Postponed Until Further Notice”.

Bexhill, July-September 1940

The week of Monday 15th July 1940 was deeply momentous - and worrying. The defence of Eastbourne, Bexhill & Hastings fell to the 134th & 136th Brigades of the British Army’s 45th Division, commanded by Major General ECA 'Teddy' Schreiber. The 136th, mainly comprised of the 9th Battalion, Devonshires, and the 4th and 5th Battalions, Duke of Cornwall's Light Infantry were based near Eastbourne; the 134th, made up of the Devonshires' 4th, 6th, and 8th Battalions were to cover Bexhill & Hastings. Hstorian David John Newbold found that a June 1940 inspection by a Brigadier George W Sutton had concluded that both brigades were “weak”. “The hinterland” up to the Downs had been left to the Home Guard to defend, Sutton added, sat behind “barricades consisting of tree trunks, old motor cars, farm carts and barbed wire trestles,” ordered “to hold their positions to the last man and the last cartridge”.

On Wednesday 17th Lt-General Sir Alan Brooke, commanding the army in southern England, met Winston Churchill and raised his doubts about the strategy devised by the overall commander of UK home defence, General Edmund ’Tiny’ Ironside. Churchill had expected the invaders to land on the East Coast north of The Wash. But that day he began to consider the possibility that they might target the South Coast instead. Unknown to both, the day before Hitler had plumped for just that option, targeting a line from Ramsgate to the Isle of Wight.

New York papers report Hitler's speech
Front page of a US paper reporting Hitler's "appeal to reason," urging Britain to come to terms with the Nazi state.

On Friday 19th Hitler made his final ‘peace offer’ in his notorious "Appeal To Reason" speech to the Reichstag. It was rejected an hour later by a BBC statement from London. The same day British Ultra codebreakers confirmed the invasion plan and its codename, Operation Sealion - but not its direction - and Brooke replaced Ironside in charge of the Army’s defence of the nation. Brooke immediately scrapped Ironside’s plan for a static ‘GHQ Line’ of inland pillboxes and river defences south of London. He planned to take the fight to the Germans, rather than wait for them to come to him.

Brooke had seen fast moving German tank attacks easily bypass fixed defences before Dunkirk. So he planned to deploy a light force along British beaches to delay the Germans while mobile Allied forces inland moved up to counterattack. The Home Guard’s meagre barricades were toughened up with concrete, sandbags and better armed men. The 45th Division was re-equipped and in September 1940 the 2nd New Zealand Division was deployed behind them in support.

Publicly, Brooke was confident: “Even should an attack have an initial success, it will certainly be destroyed before it has penetrated far.” His private diary for 26th July was more revealing. He feared the Royal Navy might not be able to prevent the Germans overwhelming his land forces with fresh reinforcements from France. He struggled with the lack of a combined command unifying the Navy, Army & Air Force. And he feared Churchill might take charge with “his impulsive nature” and preference for “intuition” over a “logical approach”.

The soldier-historian Basil Liddell Hart described “the muddles, delays and confusion” during military exercises, which led him to think British defences might have collapsed if the invasion had come in 1940. In one exercise the soldiers playing the part of the ‘invaders’ had to sit down on the beach and wait for more than 48 hours until the ‘defenders’ were ready to ‘counterattack’. “The ‘invaders’,” Liddell Hart noted, “could have pushed many miles inland by that time had they been allowed to do so, and have thrown the whole of our counterattack into paralysed confusion".

German panzers
German panzers advance through France in June 1940.

The real invaders were planning to arrive in river barges prone to swamping and limited in number. To suit the tides the landings were eventually scheduled for the days between 19-26 September 1940, with a ‘go’ order from Hitler no later than 17 September. As history tells us, on Sunday 15 September the German Luftwaffe threw all its available forces into the climatic day of the Battle of Britain, and in the wake of their defeat the order to invade England was never given. Had history turned out differently, a grim fate would have awaited Bexhill.

The town would not have been wholly unprepared for Manstein’s panzer forces. Bexhill had its Home Guard and British & New Zealander soldiers in position, almost certainly out-numbered and out-gunned by the German attackers, but by September 1940, much better prepared than the poor makeshift units that Brigadier Sutton had found two months earlier. Problematically, the attack would have come, not over the beach but from behind the town, through the village of Sidley and The Highlands to the north of Bexhill via Lunsford’s Cross. And it would have there where the first shots of the Battle of Bexhill would have been fired as a full panzer regiment – 3,200 men, artillery, and tanks - crashed south.

In charge of Bexhill’s preparations: retired Major Arthur Cecil Ticehurst MC, the commander of Bexhill’s Home Guard. Major Ticehurst came from one of the district’s most established families - an ancestor served as High Constable in the town of Battle during the Napoleonic Wars, where he was responsible for preparing for an earlier invasion that never came. An engineer by trade, he joined the Royal Engineers in 1914, was wounded in action in 1915, and returned to the front in 1917 at the head of a locally raised battalion of sappers. He was ideally qualified for the task of building defences to slow the expected German advance through Bexhill, built from ingeniously connected requisitioned buildings at key points.

Areas of Bexhill prepared for attack
From a document in the County Records Office: Areas of Bexhill and Sidley to be cleared and turned into armed strongpoints in event of invasion.

Major Ticehurst served as the military representative of the Bexhill & Sidley ‘Triumvirate’, one of three officials who would take charge in the event of German attack. The others were, representing the borough council, the Mayor, Alderman W.E. Cuthbert, and for the civilian police, a Superintendent Simmons. They identified five areas of the town to fortify against attack – in the town centre between the sea front and Magdalen Road; The Highlands north of Turkey Road; the Wheatsheaf roundabout in Little Common; a stretch of Cooden Drive and down to the sea, and south of Ninfield Road in Sidley, including what was then, and still is, Smith & Humphrey’s garage.

All the homes & businesses in these areas would be occupied by the military, and their occupants – a pre-documented 12,387 men and women, children already evacuated – moved out by order. Soldiers & Home Guard members under Major’s Ticehurst’s direction would set about converting each building in the zones – designated “defence areas” – into individual but connected strongpoints. It was a rough process, an art of war later perfected in urban battles from Stalingrad & Arnhem, to Suez, Derry, Mogadishu & Fallujah.

The methods were detailed in a series of books for the Home Guard, written by one Colonel George A Wade MC, in scientific, yet remarkably light-hearted style, illustrated in ways better suited to an Enid Blyton book. Questionable taste aside, the technique was well understood, involving careful placing of obstacles to lure or drive attackers into the defenders’ lines of fire, reinforcing floors and walls against blast, and knocking holes into walls to enable rapid fire, tactical retreats, and when the moment was right – a counterattack.

Cover of GA Wade's Book "Defence of Houses"
How to turn a Bexhill home into a lethal trap for German invaders.

News of invasion, by military signals codenamed VENEER, or by the ringing of church bells, would have triggered the call “Action Stations” setting Bexhill’s defenders to pre-assigned positions – air raid wardens, medical staff, the emergency services, and the regular army (among them a young Gunner Terence ‘Spike’ Milligan 954024, then serving with a Royal Artillery unit in Bexhill). The battle would have been fierce but inevitably brief. The defenders would have had little in the way of anti-tank guns to deal with the battle-hardened panzer crews Manstein would have assigned to take the town.

This would have been Bexhill’s war in the event of invasion. A brutal struggle on the beaches, in the town and on the downs to the north, with dozens of desperate last stands at scores of makeshift defensive positions inland. Post-war military studies suggest that Brooke’s mobile columns would have eventually beaten back an enemy starved of supplies by the Royal Navy’s Channel attacks. But in the weeks, even months that this might have taken, the human losses suffered, and the damage done to the town and its people would have been catastrophic. Mercifully, S-Day never dawned over Bexhill.

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