The invasion of Britain postponed until spring

On 12 October 1940 the Wehrmacht High Command (OKW) passed on to the commanders of the army, navy and air force Adolf Hitler’s decision on Operation Sea Lion, the landing in England. The order, signed by the chief of the OKW, Field Marshal Wilhelm Keitel, stated that the Führer had decided that from then until the spring the preparations for Sea Lion were to be maintained solely as a means of political and military pressure on England. Should the intention to land be revived in the spring or early summer of 1941, the required state of readiness would be ordered in good time. Until then the armed forces were to improve the “foundations” of the future operation while releasing men and resources not directly needed for it.

War chronologies record under this date that the invasion of Britain was postponed until the spring of 1941 “at least”. That is accurate. Some German-language studies give 15 October, but the OKW order cited by the official histories and by scholars of the German invasion plans is dated 12 October. It was the second step in the same story: on 17 September Hitler had postponed the landing until further notice; now he acknowledged that it would not take place in 1940.

Why October

The September decision had still left a door open. Hitler had then ordered that a landing in October be kept in view, and the next period in which moon and tides favoured a crossing began on 8 October. At the same time, however, he had allowed the invasion fleet to be dispersed, so that British bombers would not go on destroying it in the Channel ports. According to the British official history, by 21 September the Germans had lost or had damaged 21 of 170 transports and 214 of more than 1,900 barges. The two were mutually exclusive: a fleet being dispersed among the ports of the Netherlands, Belgium and France and along the inland canals could not quickly be reassembled. In October, therefore, Hitler had to choose between halting the dispersal and putting off the whole undertaking for longer. He chose the latter.

Everything that had happened since July argued for postponement. The condition laid down in Directive No. 16 – the defeat of the British air force – had not been met. On 15 September the Luftwaffe had lost the largest daylight battle of the campaign over London, and in October the RAF not only had not collapsed but had more reserve Hurricanes and Spitfires in its stores than in August. Autumn gales were closing the Channel ever more often to flat-bottomed river barges. Grand Admiral Erich Raeder had from the outset regarded the landing as a last resort and had spent the whole summer advising that it be put back to May 1941. The Royal Navy still ruled the waters off the British coast: on the night of 10–11 October the battleship HMS Revenge, escorted by destroyers and gunboats, shelled the port of Cherbourg.

What the order meant

The order of 12 October did not cancel Sea Lion. The army could now release for other tasks the divisions and staffs earmarked for the first wave. The navy was to return to the economy some of the ships, barges, tugs and their crews, without which shipping on the Rhine and the transport of coal were suffering. There was a single proviso: everything was to be done in such a way that the British would go on believing an invasion was imminent. The staffs were to keep practising embarkation, developing special landing equipment and continuing work on the long-range batteries on the Strait of Dover. The threat of a landing, even a sham one, tied down dozens of divisions, hundreds of guns and a large part of the fleet in England, and in Germany it provided an argument that the war against Britain was still being waged.

On the other side of the Channel the effects were seen, but the decision was unknown. British air reconnaissance counted 1,004 barges in the five main invasion ports, from Vlissingen to Boulogne, on 18 September, 691 in the last week of September, and only 448 in the last week of October. The photographs, however, also showed ramps for rapid loading and new work on airfields in the Netherlands, and intelligence feared that the Germans were preparing a fleet in the Baltic ports. Only on 29 October did a new long-range reconnaissance Spitfire photograph Szczecin (Stettin) and Świnoujście (Swinemünde) and find nothing alarming there. At the end of October the British government concluded that a major landing within the next five months could be expected at most on the south-east coast, although the defences were not relaxed.

The air war changes its aim

The postponement of the landing also changed the purpose of the German air offensive. The bombers were no longer to prepare for a landing but to break British industry, ports and civilian morale. After its daylight defeats in September, Hermann Göring sent mainly fighters and fighter-bombers over England by day – above all Messerschmitt Bf 109s carrying a single bomb – which came in at high altitude and gave the radars only a quarter of an hour or so of warning. The weight of the bombing shifted to the night. According to British sources, of some 8,200 tonnes of bombs dropped on Britain in October about nine-tenths fell after dark, and on the night of 15–16 October more than 400 bombers dropped almost 540 tonnes of high explosive on London. The night offensive, which the Germans had begun on 7 September with the raid on London, was to last until May 1941. The British regard 31 October as the end of the Battle of Britain, although for Londoners and the people of other cities the worst part of the air war was only beginning.

The peripheral strategy

The autumn of 1940 was for Hitler a time of searching for another way to defeat Britain. On 26 September Raeder argued to him in private that England could be struck where it was truly vulnerable: at Gibraltar, on the Suez Canal, in north-west Africa and in the Canary Islands, before the British, the Americans and the Free French established themselves in Africa. Such thinking is known as the peripheral strategy. Bound up with it was the idea of a “continental bloc” stretching from Spain to Japan, which was to rob London of hope of allies. That was the purpose of the Tripartite Pact concluded on 27 September and of the talks with Benito Mussolini at the Brenner Pass on 4 October, and on 13 October, the day after the OKW order, the Foreign Minister Joachim von Ribbentrop sent Joseph Stalin a letter inviting Vyacheslav Molotov to Berlin. In the second half of October Hitler travelled to meet Francisco Franco and Marshal Philippe Pétain, in an effort to win Spain and Vichy France for the war against Britain, even if only indirectly.

At the same time preparations in the east went on. As early as 31 July Hitler had told the army high command that the Soviet Union would have to be attacked in the spring of 1941, and from August the General Staff under General Franz Halder had been drawing up plans for such a war. From the autumn more and more divisions were transferred east, and a German military mission went to Romania to protect the oilfields at Ploiești. The postponement of the landing freed forces and attention for these plans.

Place in the war

The order of 12 October marked the end of the plans to invade Britain in 1940 and, in practice, altogether. Directive No. 18 of 12 November still listed Sea Lion as an operation possible in the spring of 1941, but dealt mainly with Gibraltar (Operation Felix), Greece and North Africa. The talks with Molotov in November produced no agreement, and on 18 December 1940 Hitler signed Directive No. 21 on the invasion of the Soviet Union. In the spring of 1941 the invasion preparations, renamed Haifisch (“Shark”) and supplemented by the feint landings of Harpune, served solely as a screen for the concentration of troops in the east. In September 1941 Hitler ordered the preparations to be halted, and the last barges assembled at Antwerp returned to commercial shipping only in 1942. The operation was never formally cancelled, and the landing equipment built in 1940 later proved useful in operations in the Baltic.

For Britain the postponement of the invasion meant that it had survived the most dangerous period of the war. It did not yet know this and kept its coastal defences at the ready all winter, but it gained time to rebuild the army after Dunkirk, to take in American aid and to wage war in Africa and the Mediterranean. For Germany it was the first great undertaking from which Hitler had to back down. Instead of ending the war in the west, he began one in the east, leaving behind him an undefeated Britain, which in time became the base for the Allied bombing offensive and for the Normandy landings in 1944.