Directive No. 17

On 1 August 1940 Adolf Hitler signed the secret “Weisung Nr. 17 für die Führung des Luft- und Seekrieges gegen England”, Directive No. 17 for the conduct of air and sea warfare against England. It opened with the sentence: “In order to establish the necessary conditions for the final conquest of England, I intend to intensify air and sea warfare against the English homeland.” In practice it was an order to the Luftwaffe to strike at the British air force with all its strength. Two weeks earlier Hitler had ordered preparations for a landing in England, Operation Sea Lion, and had made it conditional on the defeat of the British air force. Directive No. 17 was meant to fulfil that condition.

Chronologies often state under this date that Hitler “set 15 September as the date for Operation Sea Lion”, and under 5 August that “lack of air superiority and bad weather over the Channel” caused the invasion to be postponed. Both statements need correcting. 15 September was not the date of the landing but the deadline by which preparations were to be complete, and Hitler intended to decide on the landing itself only after the first weeks of the air battle. Nor was the invasion postponed on 5 August: that was the earliest day from which the directive allowed the intensified air war to begin. Bad weather did indeed delay the Luftwaffe’s great offensive, which did not get under way until 13 August. Sea Lion was not postponed until September. Both matters concern the same order and its execution.

The conference at the Berghof

The directive was the outcome of a conference Hitler held on 31 July at the Berghof, his residence in the Bavarian Alps. The head of the navy, Grand Admiral Erich Raeder, reported there that converting river barges into landing craft would take until mid-September, and that the only possible landing dates in 1940 would be 22–26 September, when the weather in the English Channel usually begins to deteriorate. He proposed postponing the operation until May 1941. Hitler refused, because the British army was growing stronger with every week. The Luftwaffe had no representative at the Berghof, yet everything now depended on it. Hitler decided that the intensified air war would begin around 5 August and that after eight to fourteen days he would decide whether the landing would take place that year.

The same day, after Raeder had left, he told the commander of the army, Field Marshal Walther von Brauchitsch, and the Chief of the General Staff, General Franz Halder, that England was counting on Russia and America and that the Soviet Union would have to be attacked in the spring of 1941. The war with England did not cease to matter to him, but from that day on the army staffs began to think above all about the east.

On 1 August Hitler signed Directive No. 17. That same day the Chief of the Armed Forces High Command (OKW), Field Marshal Wilhelm Keitel, sent the three services a memorandum setting out the decisions taken at the Berghof. Preparations for Operation Sea Lion were to continue so that they would be complete by 15 September. Eight to fourteen days after the start of the air offensive, planned for around 5 August, the Führer would decide whether the landing would take place in 1940. If not, preparations were to continue with May 1941 in view. That is the origin of the date of 15 September, which many chronicles present as the date fixed for the invasion.

The content of the directive

Directive No. 17 was short. It had six points:

1. The Luftwaffe was “to overpower the English air force with all the forces at its command, in the shortest possible time”. Its attacks were to be directed primarily against flying units, their ground organisation and their supply installations, and then against the aircraft industry, including factories producing anti-aircraft equipment.
2. Once temporary or local air superiority had been achieved, the air war was to be continued against ports, in particular food stores, and against food stocks inland. Ports on the south coast, needed for Germany’s own landing operation, were to be attacked as little as possible.
3. Attacks on warships and merchant ships could be reduced, unless a particularly favourable target presented itself or they were needed for training crews.
4. The Luftwaffe was to remain constantly ready to support naval operations and to take part with its full strength in Operation Sea Lion.
5. “I reserve to myself the right to decide on terror attacks as measures of reprisal.”
6. The intensified air war could begin on or after 5 August. The exact date was to be fixed by the Luftwaffe itself, once its preparations were complete and depending on the weather. At the same time the navy could begin intensified warfare at sea.

The directive thus shifted the weight of effort. In July the German air force had fought mainly over convoys in the English Channel, and British airmen date the beginning of the Battle of Britain to 10 July. Now the main target was to be the Royal Air Force’s fighters and their airfields, with shipping only incidentally. Point five, seemingly secondary, later proved very important: it forbade unauthorised bombing of cities while leaving Hitler free to order it should he regard it as reprisal.

Not everything in the directive was consistent. Hitler did not settle whether the Luftwaffe’s chief task was to prepare the landing or to bring England to its knees on its own by destroying its air force, ports and supplies. Many in Berlin, Göring first among them, hoped that after a few weeks of raids the British would sue for peace and a landing would not be needed.

Göring’s plan

Carrying out the directive fell to the commander of the Luftwaffe, Reichsmarschall Hermann Göring, who since 19 July had held this new rank, created specially for him. Göring was self-confident. After Dunkirk he had already assured Hitler that his air force could deal with England, and in July he saw no reason to think otherwise. On 1 August he gathered the commanders of the units operating against England in The Hague. According to the recollections of one of those present, the fighter commander Oberst Theo Osterkamp, Göring declared that the Führer had ordered him to bring Britain to its knees, and expected to win air superiority within a few days. Osterkamp warned that the British fighters were numerous and good, but Göring would not listen.

The final plan for “Adlerangriff” (“Eagle Attack”) was agreed on 6 August at a conference at Carinhall, Göring’s country estate north of Berlin. Present were the Inspector General of the Luftwaffe, Field Marshal Erhard Milch; the commander of Luftflotte 2, Field Marshal Albert Kesselring; the commander of Luftflotte 3, Field Marshal Hugo Sperrle; and the commander of Luftflotte 5 in Norway, General Hans-Jürgen Stumpff. Kesselring and Sperrle had different ideas: Sperrle proposed striking above all at the ports through which the island’s supplies flowed, while Kesselring wanted to force the British fighters into battle by attacking targets they had to defend. A plan spread over a dozen or more days was adopted. Under Göring’s order, British air defences and the RAF airfields in southern England were to be smashed within four days, and over the following weeks attacks were to be pushed ever deeper, ever closer to London, destroying aircraft factories. The first day of the great offensive was named “Adlertag”, Eagle Day. According to most accounts it was provisionally set for 10 August.

Intelligence failures

The plan rested on a false picture of the enemy. The head of the Luftwaffe’s intelligence branch, Oberst Joseph (“Beppo”) Schmid, had presented an assessment in July according to which the RAF had few airfields in southern England, its command was rigid and its fighters tied to their bases. British industry, he claimed, was producing between 180 and 330 fighters a month, and fewer all the time, so the RAF could not withstand a long war of attrition. In reality British factories delivered nearly 500 fighters in July, more than the Germans were building Messerschmitts. Since May aircraft production had been in the hands of a new minister, Lord Beaverbrook, who stopped at nothing to get as many Hurricanes and Spitfires as possible out of the factories. According to British figures, at the beginning of August Fighter Command had some 1,400 pilots and was only a hundred and fifty or so short of full establishment.

The gravest error concerned radar. The Germans knew about the tall masts of the Chain Home stations on the coast, but did not understand that they were part of the integrated defence system built by the head of Fighter Command, Hugh Dowding. Schmid’s report did not mention radar at all. Some on the Luftwaffe staff even believed that British radar would help the Germans by drawing the RAF’s fighters into great battles in which they would be destroyed. Intelligence was also unable to distinguish Fighter Command airfields from those of Bomber Command and Coastal Command, so many of the planned attacks were bound to hit targets whose destruction would do nothing to weaken the British fighters.

The weather and Eagle Day

The first days of August did not bring the promised offensive. The Luftwaffe was completing its preparations, and low cloud and rain hung over England and the Channel. In London, meanwhile, an invasion was expected. British commanders believed the Germans might exploit the tides of 5–9 August, and the coastal defences were on a heightened state of alert. Yet 5 August, the date from which Hitler had allowed the air war to be intensified, passed without major raids, and on 8 August, in better weather, the Germans threw large numbers of aircraft against a single convoy, which the British called “Peewit”. The fighting over it was the heaviest since the beginning of July, and in its first accounts the British Air Ministry even took that day as the start of the Battle of Britain.

On 10 August the weather was bad again and Adlertag was postponed. On 11 August the Germans attacked the naval base at Portland; on 12 August they struck for the first time at the radar stations on the coasts of Kent and Sussex and on the Isle of Wight, and at coastal RAF airfields. Most of the stations were working again the same day or the next morning; only the station at Ventnor on the Isle of Wight was out of action for many days. Göring fixed Adlertag for 13 August. That morning it was cloudy again, and at the last moment he ordered the raids held back until the afternoon, but not all units received the order in time. The great offensive that the directive had allowed to begin from 5 August thus opened eight days late, and in confusion.

That is how the report of the “invasion postponed because of the lack of air superiority and bad weather” should be understood. At the beginning of August it was the Luftwaffe’s offensive that was delayed, not the landing. The timetable for Sea Lion changed for other reasons: throughout August the army and the navy argued over whether to land on a broad or a narrow front. At the end of August Hitler imposed a compromise, and the navy, whose preparations were behind schedule, moved the earliest date to 20–21 September.

Place in the war

Directive No. 17 opened the hardest period of the Battle of Britain. From 13 August the Luftwaffe attacked airfields, radar stations and aircraft factories, and at the end of August and the beginning of September, when it struck at the sector airfields of Air Vice-Marshal Keith Park’s No. 11 Group, Fighter Command went through its most difficult weeks. At the end of August the Polish No. 303 Squadron entered the fighting. The intensified war at sea that the directive had allowed the navy led on 17 August to Germany’s declaration of a total blockade of the British Isles.

None of the conditions, however, was met. The British air force was not defeated in four days, nor in four weeks. Point five of the directive soon gained significance: after German bombs fell on London on the night of 24–25 August and the RAF bombed Berlin in response, Hitler announced reprisals against British cities on 4 September, and on 7 September the Luftwaffe turned its bombers against London. This relieved the RAF’s airfields. On 15 September, the day on which preparations for the landing were to have been complete, the great German daylight raids on London were beaten off with heavy losses. On 17 September Hitler postponed Operation Sea Lion indefinitely, and on 12 October he put it off until the spring of 1941. By then his attention was already turned to the east.

Directive No. 17 also exposed the weakness of German command in the war against England. Hitler left Göring free to choose targets and dates, and Göring, badly informed by his own intelligence, promised a quick victory he could not deliver. The Luftwaffe, built to support ground forces on the Continent, was expected to defeat a modern, well-organised air defence on its own – and with fighters that could stay over London for only a dozen or so minutes. The Battle of Britain became the Third Reich’s first serious defeat of the war.