The Battle of Britain

Page 5 – The battle: September-October

Tactical disputes

In early September 1940 Britons steeled themselves for the German invasion that now seemed imminent. As Royal Air Force (RAF) Fighter Command found itself on the verge of defeat, Air Vice-Marshal Keith Park had to contend with a distracting disagreement over tactics. Faced with multiple raids and little time to deploy his units, he had scrambled single squadrons to make interceptions. Their success depended on rapidly reaching the optimum altitude to attack the oncoming Luftwaffe (German air force) bombers or to defend themselves from escorting fighters. This approach helped Park's No. 11 Group break up or disrupt many of the raids before they reached their targets.

Often No. 12 Group, less directly in the line of attack, was tasked to protect airfields while No. 11 Group’s aircraft fought the raiders. Among No. 12 Group, with more time to develop their response, the belief in combining squadrons grew – the so-called Big Wing approach, advocated by Air Vice-Marshal Trafford Leigh-Mallory. These massed formations of fighters could, it was asserted, have a decisive impact against an enemy bomber force. Opponents pointed out that the time taken to form up a wing meant that it would likely strike at enemy bombers only after they had dropped their bombs and were heading home.

Although he considered the Big Wing approach impracticable in the circumstances confronting his group, Park did employ two-squadron formations where possible later in the battle. His superior, Air Marshal Hugh Dowding, agreed with Park’s approach, later noting that ‘If the policy of big formations had been attempted at this time in No. 11 Group, many more German bombers would have reached their objective without opposition.’ With benefit of experience in later commands, Park was convinced that ‘we would have lost the Battle of Britain if I had adopted the “withholding” tactics of No. 12 Group’.

The battle: third phase

Had the Germans pressed on with their attacks on the airfields tactical issues might rapidly have lost relevance as Fighter Command’s very existence was at stake. But on 7 September 1940 a change of German strategy let the RAF off the hook. On that day a bomber force attacked London, the first heavy daylight raid. It quickly became apparent that this was no random event - a succession of raids on the capital followed. From this time night bombing raids on London, which had happened on occasions over previous weeks, also became more intense. With its airfields no longer the primary Luftwaffe target, Fighter Command was provided with a respite, which it used to good effect to restore its position.

The reason for this change of strategy - later seen as the decisive moment in the battle - remains unclear. One explanation is that Hitler demanded that the Luftwaffe bomb London in retaliation for an RAF bombing raid on Berlin on the night of 25-26 August - a raid that was itself retaliation for the first major Luftwaffe bombing attack on London the previous night. On 2 September orders were issued to Air Fleets 2 and 3 to mount a ‘retaliatory attack on London’. Another explanation is that Luftwaffe leader Hermann Göring recognised that the necessary conditions for Operation Sea Lion could not be attained, and hoped that attacks on British population centres might bring about a collapse of morale, encouraging acceptance of German peace offers.

Underlying the changed German strategy was more likely an over-estimation of the damage that had been done to Fighter Command in the preceding weeks. German intelligence estimates put its strength at no more than 300 machines, when in fact it had more than double that figure. Hitler and Göring may have assumed that this remnant could be destroyed while trying to prevent the raids on London, and that this might yet open the way for a landing.

The change of strategy occurred just four days before the scheduled order to launch Operation Sea Lion. If there were hopes that a devastating attack on the capital might cripple Fighter Command, they were quickly dispelled as No. 11 Group, assisted by No. 12 Group, took a heavy toll of the German bombers. The evidence of continuing resistance led to postponement, on 9 September, of the Sea Lion launching order by three days, soon extended by another three days. These delays did nothing for the morale of the German aircrews, who were aware of the RAF’s continued potency. Losses mounted alarmingly.

On 15 September the Luftwaffe made a supreme effort. A series of raids battered the capital all day, fiercely contested by some 300 British fighters. Park committed his whole force. When the visiting Prime Minister, Churchill, asked him about reserves, he replied, ‘There are none.’ About 60 German planes were destroyed during the day - though at the time a morale boosting 185 was announced.

With no end to British resistance in sight, and the adverse weather of autumn approaching, Hitler accepted that Operation Sea Lion must be postponed at least until the following year. On 17 September he put it off ‘until further notice’, and then on 2 October he ordered most of the preparations to be dismantled. The dispersal of invasion vessels was soon being noted by RAF reconnaissance aircraft. In the meantime, the Luftwaffe continued to batter London and other British cities, an onslaught that would continue well into 1941.

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'The battle: September-October', URL:, (Ministry for Culture and Heritage), updated 20-Dec-2012