Editing Battle of Britain (section)

==Phases of the battle==
[[File:Bundesarchiv Bild 141-0678, Flugzeuge Heinkel He 111.jpg|thumb|right|German Heinkel He 111 bombers over the English Channel 1940]]
The battle covered a shifting geographical area, and there have been differing opinions on significant dates: when the Air Ministry proposed 8 August as the start, Dowding responded that operations "merged into one another almost insensibly", and proposed 10 July as the onset of increased attacks.{{sfn|Overy|2001|pp=61–62}} With the caution that phases drifted into each other and dates are not firm, the [[Royal Air Force Museum]] states that five main phases can be identified:<ref name="RAF Museum phases">{{cite web | title=Introduction to the Phases of the Battle – History of the Battle of Britain – Exhibitions & Displays – Research | website=RAF Museum | url=http://www.rafmuseum.org.uk/research/online-exhibitions/history-of-the-battle-of-britain/introduction-to-the-phases-of-the-battle-of-britain.aspx | access-date=28 March 2016}}</ref>
* 26 June – 16 July: ''Störangriffe'' ("nuisance raids"), scattered small scale probing attacks both day and night, armed reconnaissance and mine-laying sorties. From 4 July, daylight ''[[Kanalkampf]]'' ("[[English Channel|the Channel]] battles") against shipping.
* 17 July – 12 August: daylight ''Kanalkampf'' attacks on shipping intensify through this period, increased attacks on ports and coastal airfields, night raids on RAF and aircraft manufacturing.
* 13 August – 6 September: ''[[Adlerangriff]]'' ("Eagle Attack"), the main assault; attempt to destroy the RAF in southern England, including massive daylight attacks on RAF airfields, followed from 19 August by heavy night bombing of ports and industrial cities, including suburbs of London.
* 7 September – 2 October: [[the Blitz]] commences, main focus day and night attacks on London.
* 3–31 October: large scale night bombing raids, mostly on London; daylight attacks now confined to small scale fighter-bomber ''Störangriffe'' raids luring RAF fighters into dogfights.

===Small scale raids===
Following Germany's rapid territorial gains in the Battle of France, the Luftwaffe had to reorganise its forces, set up bases along the coast, and rebuild after heavy losses. It began small scale bombing raids on Britain on the night of 5/6 June, and continued sporadic attacks throughout June and July.{{sfn|Overy|2001|pp=47–49, 61}} The first large-scale attack was at night, on 18/19 June, when small raids scattered between Yorkshire and Kent involved in total 100 bombers.{{sfn|Bishop|2010|p=54}} These ''Störangriffe'' ("nuisance raids") which involved only a few aeroplanes, sometimes just one, were used to train bomber crews in both day and night attacks, to test defences and try out methods, with most flights at night. They found that, rather than carrying small numbers of large high explosive bombs, it was more effective to use more small bombs, similarly incendiaries had to cover a large area to set effective fires. These training flights continued through August and into the first week of September.{{sfn|Overy|2013|pp=71–72}} Against this, the raids also gave the British time to assess the German tactics, and invaluable time for the RAF fighters and anti-aircraft defences to prepare and gain practice.{{sfn|Overy|2001|p=66}}

[[File:Interior of RAF Fighter Command's Sector 'G' Operations Room at Duxford, Cambridgeshire, September 1940. CH1401.jpg|thumb|Interior of RAF Fighter Command's [[RAF Fighter Command Order of Battle 1940|Sector 'G']] Operations Room at [[Duxford Aerodrome|Duxford]], 1940]]
The attacks were widespread: over the night of 30 June alarms were set off in 20 counties by just 20 bombers, then next day the first daylight raids were carried out during 1 July, on both [[Kingston upon Hull|Hull in Yorkshire]] and [[Wick, Caithness]]. On 3 July most flights were reconnaissance sorties, but 15 civilians were killed when bombs hit [[Guildford]] in Surrey.{{sfn|Bishop|2010|pp=80–81}} Numerous small ''Störangriffe'' raids, both day and night, were made daily through August, September and into the winter, with aims including bringing RAF fighters up to battle, destruction of specific military and economic targets, and setting off air-raid warnings to affect civilian morale: four major air-raids in August involved hundreds of bombers; in the same month 1,062 small raids were made, spread across the whole of Britain.{{sfn|Overy|2013|p=80}}

===Channel battles===
The ''[[Kanalkampf]]'' comprised a series of running fights over convoys in the English Channel. It was launched partly because Kesselring and [[Hugo Sperrle|Sperrle]] were not sure about what else to do, and partly because it gave German aircrews some training and a chance to probe the British defences.{{sfn|Bungay|2000|p=122}} Dowding could provide only minimal shipping protection, and these battles off the coast tended to favour the Germans, whose bomber escorts had the advantage of altitude and outnumbered the RAF fighters. From 9 July reconnaissance probing by [[Dornier Do 17]] bombers put a severe strain on RAF pilots and machines, with high RAF losses to Bf 109s. When nine [[No. 141 Squadron RAF|141 Squadron]] [[Boulton Paul Defiant|Defiants]] went into action on 19 July six were lost to Bf 109s before a squadron of [[Hawker Hurricane|Hurricanes]] intervened. On 25 July a coal convoy and escorting destroyers suffered such heavy losses to attacks by [[Junkers Ju 87|Stuka]] [[dive bomber]]s that the [[British Admiralty|Admiralty]] decided convoys should travel at night: the RAF shot down 16 raiders but lost 7 aircraft. By 8 August 18 coal ships and 4 destroyers had been sunk, but the Navy was determined to send a convoy of 20 ships through rather than move the coal by railway. After repeated Stuka attacks that day, six ships were badly damaged, four were sunk and only four reached their destination. The RAF lost 19 fighters and shot down 31 German aircraft. The Navy now cancelled all further convoys through the Channel and the cargo was sent by rail. Even so, these early combat encounters provided both sides with experience.<ref>{{harvnb|Deighton|Hastings|1980|pp=154–183}}</ref>

===Main assault===
The main attack upon the RAF's defences was code-named ''Adlerangriff'' ("Eagle Attack"). Intelligence reports gave Göring the impression that the RAF was almost defeated, and raids would attract British fighters for the Luftwaffe to shoot down.{{sfn|Bungay|2000|pp=123–125}} The strategy agreed on 6 August was to destroy RAF Fighter Command across the south of England in four days, then bombing of military and economic targets was to systematically extend up to the Midlands until daylight attacks could proceed unhindered over the whole of Britain, culminating in a major bombing attack on London.{{sfn|Overy|2001|pp=56–57, 61–62}}{{sfn|Overy|2013|pp=82–83, 85}}

====Assault on RAF: radar and airfields====
[[File:East Coast Chain Home radar station CH15176.jpg|thumb|East Coast [[Chain Home]] radar operators.]]
Poor weather delayed ''[[Adlertag]]'' ("Eagle Day") until 13 August 1940. On 12 August, the first attempt was made to blind the Dowding system, when aircraft from the specialist fighter-bomber unit [[Erprobungskommando#Erprobungsgruppe 210|''Erprobungsgruppe'' 210]] attacked four [[Chain Home|radar stations]]. Three were briefly taken off the air but were back working within six hours.<ref name="Bungay, 2000, pp. 203–205">{{harvnb|Bungay|2000|pp=203–205}}</ref> The raids appeared to show that British radars were difficult to knock out. The failure to mount follow-up attacks allowed the RAF to get the stations back on the air, and the Luftwaffe neglected strikes on the supporting infrastructure, such as phone lines and power stations, which could have rendered the radars useless, even if the lattice-work towers themselves, which were very difficult to destroy, remained intact.<ref name="Allen"/>

''Adlertag'' opened with a series of attacks, led again by ''Erpro'' 210,<ref name="Bungay, 2000, pp. 203–205"/> on coastal airfields used as forward landing grounds for the RAF fighters, as well as 'satellite airfields'<ref group=nb>"Satellite" airfields were mostly fully equipped but did not have the sector control room which allowed "Sector" airfields such as Biggin Hill to monitor and control RAF fighter formations. RAF units from Sector airfields often flew into a satellite airfield for operations during the day, returning to their home airfield in the evenings.</ref> including [[RAF Manston|Manston]] and [[RAF Hawkinge|Hawkinge]].<ref name="Bungay, 2000, pp. 203–205" /> As the week drew on, the airfield attacks moved further inland, and repeated raids were made on the radar chain. 15 August was "The Greatest Day" when the Luftwaffe mounted the largest number of sorties of the campaign. ''Luftflotte'' 5 attacked the north of England. Raiding forces from Denmark and Norway, which believed Fighter Command strength to be concentrated in the south, ran into resistance which was unexpectedly strong. Inadequately escorted by Bf 110s, Bf109s having insufficient range to escort raids from Norway, bombers were shot down in large numbers. North East England was attacked by 65 Heinkel 111s escorted by 34 Messerschmitt 110s, and [[RAF Driffield|RAF Great Driffield]] was attacked by 50 unescorted Junkers 88s. Out of 115 bombers and 35 fighters sent, 75 planes were destroyed and many others were damaged beyond repair. Furthermore, due to early engagement by RAF fighters, many of the bombers dropped their payloads ineffectively early.<ref>[http://www.battleofbritain1940.net/document-32.html "Document 32.] {{Webarchive|url=https://web.archive.org/web/20110723024634/http://www.battleofbritain1940.net/document-32.html |date=23 July 2011 }} ''Battle of Britain Historical Society''. Retrieved: 19 March 2015.</ref> As a result of these casualties, ''Luftflotte'' 5 did not appear in strength again in the campaign.
[[File:Pilots of No. 310 (Czechoslovak) Squadron RAF in front of Hawker Hurricane Mk I at Duxford, Cambridgeshire, 7 September 1940. CH1299.jpg|thumb|[[Czechoslovakia|Czechoslovak]] fighter pilots of [[No. 310 Squadron RAF]] at [[RAF Duxford]] in 1940]]

18 August, which had the greatest number of casualties to both sides, has been dubbed "[[The Hardest Day]]". Following this grinding battle, exhaustion and the weather reduced operations for most of a week, allowing the Luftwaffe to review their performance. "The Hardest Day" had sounded the end for the Ju 87 in the campaign.<ref>{{harvnb|Price|1980|p=179}}</ref> This veteran of ''Blitzkrieg'' was too vulnerable to fighters to operate over Britain. Göring withdrew the ''Stuka'' from the fighting to preserve the ''Stuka'' force, removing the main Luftwaffe precision-bombing weapon and shifting the burden of pinpoint attacks onto the already-stretched ''Erpro'' 210. The Bf 110 proved too clumsy for dogfighting with single-engined fighters, and its participation was scaled back. It would be used only when range required it or when sufficient single-engined escort could not be provided for the bombers.
[[File:Pilots of No. 19 Squadron RAF relax in the crew room at Fowlmere, the satellite airfield to Duxford in Cambridgeshire, September 1940. CH1461.jpg|thumb|Pilots of [[No. 19 Squadron RAF]] relax in the crew room at [[RAF Fowlmere]], 1940]]
Göring made yet another important decision: to order more bomber escorts at the expense of free-hunting sweeps. To achieve this, the weight of the attack now fell on ''Luftflotte'' 2, and the bulk of the Bf 109s in ''[[Luftflotte 3]]'' were transferred to Kesselring's command, reinforcing the fighter bases in the [[Pas-de-Calais]]. Stripped of its fighters, ''Luftflotte 3'' would concentrate on the night bombing campaign. Göring, expressing disappointment with the fighter performance thus far in the campaign, also made sweeping changes in the command structure of the fighter units, replacing many ''[[Geschwaderkommodore]]'' with younger, more aggressive pilots such as  Adolf Galland and [[Werner Mölders]].<ref>{{harvnb|Deighton|1996|p=182}}</ref>

Finally, Göring stopped the attacks on the radar chain. These were seen as unsuccessful, and neither the ''[[Reichsmarschall]]'' nor his subordinates realised how vital the Chain Home stations were to the defence systems. It was known that radar provided some early warning of raids, but the belief among German fighter pilots was that anything bringing up the "[[Tommy Atkins|Tommies]]" to fight was to be encouraged.{{citation needed|date=October 2017}}

====Raids on British cities====
On the afternoon of 15 August, ''Hauptmann'' [[Walter Rubensdörffer]] leading ''Erprobungsgruppe'' 210 mistakenly bombed [[Croydon Airport|Croydon airfield]] (on the outskirts of London) instead of the intended target, [[RAF Kenley]].<ref>{{harvnb|Korda|2010|pp=197–198}}</ref> German intelligence reports made the Luftwaffe optimistic that the RAF, thought to be dependent on local air control, was struggling with supply problems and pilot losses. After a raid on [[London Biggin Hill Airport#History|Biggin Hill]] on 18 August, Luftwaffe aircrew said they had been unopposed, the airfield was "completely destroyed", and asked, "Is England already finished?" In accordance with the strategy agreed on 6 August, defeat of the RAF was to be followed by bombing military and economic targets, systematically extending up to the Midlands.{{sfn|Overy|2013|pp=81–82}}

Göring ordered attacks on aircraft factories on 19 August 1940.<ref name="Taylor and Mayer p.74">{{harvnb|Taylor|Mayer|1974|p=74}}</ref> Sixty raids on the night of 19/20 August targeted the aircraft industry and harbours, and bombs fell on suburban areas around London: [[Croydon]], [[Wimbledon, London|Wimbledon]] and [[Municipal Borough of Malden and Coombe|the Maldens]].{{sfn|Overy|2013|p=82}} Night raids were made on 21/22 August on [[Aberdeen]], [[Bristol]] and [[South Wales]]. That morning, bombs were dropped on [[Harrow, London|Harrow]] and [[Wealdstone]], on the outskirts of London. Overnight on 22/23 August, the output of an aircraft factory at [[Filton]] near Bristol was drastically affected by a raid in which Ju 88 bombers dropped over {{cvt|16|LT}} of high explosive bombs. On the night of 23/24 August over 200 bombers attacked the [[Fort Dunlop]] tyre factory in [[Birmingham]], with a significant effect on production. A bombing campaign began on 24 August with the largest raid so far, killing 100 in [[Portsmouth]], and that night, several areas of London were bombed; the [[East End of London|East End]] was set ablaze and bombs landed on central London. Some historians believe that these bombs were dropped accidentally by a group of [[Heinkel He 111]]s which had failed to find their target; this account has been contested.<ref name="19-24aug">Putland, Alan L. [http://www.battleofbritain1940.net/0029.html "19 August – 24 August 1940."] {{Webarchive|url=https://web.archive.org/web/20091210220107/http://www.battleofbritain1940.net/0029.html |date=10 December 2009 }} ''Battle of Britain Historical Society''. Retrieved: 12 August 2009.</ref>

More night raids were made around London on 24/25 August, when bombs fell on Croydon, [[Banstead]], [[Lewisham]], [[Uxbridge]], [[Harrow, London|Harrow]] and [[Hayes, Hillingdon|Hayes]]. London was on red alert over the night of 28/29 August, with bombs reported in [[Finchley]], [[St Pancras, London|St Pancras]], [[Wembley]], [[Wood Green]], [[Southgate, London|Southgate]], [[Old Kent Road]], [[Mill Hill]], [[Ilford]], [[Chigwell]] and [[Hendon]].{{sfn|Overy|2013|pp=82–83}}

====Attacks on airfields from 24 August====
[[File:Pilots of No. 303 (Polish) Squadron RAF with one of their Hawker Hurricanes, October 1940. CH1535.jpg|thumb|right|Polish [[No. 303 Squadron RAF|303 Squadron]] pilots, 1940. Left to right: P/O [[Mirosław Ferić|Ferić]], Flt Lt [[John A. Kent|Kent]], F/O Grzeszczak, P/O Radomski, P/O [[Jan Zumbach|Zumbach]], P/O [[Witold Łokuciewski|Łokuciewski]], F/O [[Zdzisław Henneberg|Henneberg]], Sgt. Rogowski, Sgt. Szaposznikow.]]
Göring's directive issued on 23 August 1940 ordered ceaseless attacks on the aircraft industry and on RAF ground organisation to force the RAF to use its fighters, continuing the tactic of luring them up to be destroyed, and added that focussed attacks were to be made on RAF airfields.<ref name="19-24aug"/>

From 24 August onwards, the battle was a fight between Kesselring's ''Luftflotte'' 2 and Park's 11 Group. The Luftwaffe concentrated all their strength on knocking out Fighter Command and made repeated attacks on the airfields. Of the 33 heavy attacks in the following two weeks, 24 were against airfields. The key sector stations were hit repeatedly: [[RAF Biggin Hill|Biggin Hill]] and [[RAF Hornchurch|Hornchurch]] four times each; [[RAF Debden|Debden]] and [[North Weald airfield|North Weald]] twice each. [[Croydon Airport|Croydon]], [[Gravesend Airport|Gravesend]], [[London Southend Airport|Rochford]], [[RAF Hawkinge|Hawkinge]] and [[RAF Manston|Manston]] were also attacked in strength. [[Coastal Command]]'s [[RAF Eastchurch|Eastchurch]] was bombed at least seven times because it was believed to be a Fighter Command aerodrome. At times these raids caused some damage to the sector stations, threatening the integrity of the Dowding system.

To offset some losses, some 58 Fleet Air Arm fighter pilot volunteers were seconded to RAF squadrons, and a similar number of former Fairey Battle pilots were used. Most replacements from [[Operational Conversion Unit|Operational Training Units]] (OTUs) had as little as nine hours flying time and no gunnery or air-to-air combat training. At this point, the [[Battle of Britain Foreign Contribution|multinational nature of Fighter Command]] came to the fore. Many squadrons and personnel from the air forces of the [[British Dominions|Dominions]] were already [[List of Royal Air Force aircraft squadrons|attached to the RAF]], including top-level commanders – Australians, Canadians, New Zealanders, [[Rhodesia]]ns and South Africans. Other nationalities were also represented, including [[Free French Forces|Free French]], Belgian and a Jewish pilot from the [[Mandatory Palestine|British mandate of Palestine]].

They were bolstered by the arrival of fresh Czechoslovak and [[Polish Air Forces in France and Great Britain|Polish squadrons]]. These had been held back by Dowding, who thought non-English speaking aircrew would have trouble working within his control system, but Polish and Czech fliers proved to be especially effective. The pre-war [[Polish Air Force]] had lengthy and extensive training, and high standards; with Poland conquered and under [[World War II crimes in Poland|brutal]] [[Occupation of Poland (1939–1945)|German occupation]], the pilots of [[No. 303 Polish Fighter Squadron|No. 303 (Polish) Squadron]], which became the highest-scoring Allied unit,<ref name="Zaloga and Hook 1982, p. 15"/> were experienced and strongly motivated. [[Josef František]], a Czech regular airman who had flown from the occupation of his own country to join [[Invasion of Poland|the Polish]] and then French air forces before arriving in Britain, flew as a guest of 303 Squadron and was ultimately credited with the highest "RAF score" in the Battle of Britain.<ref>{{harvnb|Deighton|1996|pp=188, 275}}</ref>

The RAF had the advantage of fighting over home territory. Pilots who bailed out after being shot down could be back at their airfields within hours, and aircraft low on fuel or ammunition could be immediately re-equipped.<ref>{{harvnb|Holland|2011|pp=760. 657–658}}</ref> One RAF pilot interviewed in late 1940 had been shot down five times during the Battle of Britain, but was able to crash-land in Britain or bail out each time.<ref>{{harvnb|Ingersoll|1940|pp=159–169}}</ref> For Luftwaffe aircrews, a bailout or crash landing in England meant capture – in the critical August period, almost as many Luftwaffe pilots were taken prisoner as were killed<ref>{{harvnb|Holland|2011|p=658}}</ref> – while parachuting into the English Channel often meant drowning. Morale began to suffer, and ''Kanalkrankheit'' ("Channel sickness") – a form of [[Combat stress reaction|combat fatigue]] – began to appear among the German pilots. Their replacement problem became worse than the British.

====Assessment of attempt to destroy the RAF====
The effect of the German attacks on airfields is unclear. According to [[Stephen Bungay]], Dowding, in a letter to [[Hugh Trenchard]]<ref>the PRO, AIR 19/60.</ref> accompanying Park's report on the period 8 August – 10 September 1940, states that the Luftwaffe "achieved very little" in the last week of August and the first week of September. The only Sector Station to be shut down operationally was [[Biggin Hill]], and it was non-operational for just two hours. Dowding admitted that 11 Group's efficiency was impaired but, despite serious damage to some airfields, only two out of 13 heavily attacked airfields were down for more than a few hours. The German refocus on London was not critical.<ref name="Bungay 2000, pp. 368-369">{{harvnb|Bungay|2000|pp=368–369}}</ref>

Retired Air Vice-Marshal [[Peter Dye]], head of the RAF Museum, discussed the logistics of the battle in 2000<ref name="Dye00.">{{harvnb|Dye|2000|pp=1, 31–40}}</ref> and 2010,<ref name="Dye2010.">Dye, Air Vice Marshal Peter. ''Aeroplane'', Issue July 2010, p. 33.</ref> dealing specifically with the single-seat fighters. He said that not only was British aircraft production replacing aircraft, but replacement pilots were keeping pace with losses. The number of pilots in RAF Fighter Command increased during July, August and September. The figures indicate the number of pilots available never decreased: from July, 1,200 were available; from 1 August, 1,400; in September, over 1,400; in October, nearly 1,600; by 1 November, 1,800. Throughout the battle, the RAF had more fighter pilots available than the Luftwaffe.<ref name="Dye00."/><ref name="Dye2010."/> Although the RAF's reserves of single-seat fighters fell during July, the wastage was made up for by an efficient [[Civilian Repair Organisation]] (CRO), which by December had repaired and put back into service some 4,955 aircraft,<ref>{{harvnb|Dye|2000|p=33}}</ref> and by aircraft held at Air Servicing Unit (ASU) airfields.<ref>{{harvnb|Dye|2000|pp=33, 37}}</ref>
[[File:RAF Fighter Command 1940 HU104508.jpg|thumb|Pilots of [[No. 66 Squadron RAF|No. 66 Squadron]] at [[RAF Gravesend|Gravesend]], September 1940]]

[[Richard Overy]] agrees with Dye and Bungay. Overy says that only one airfield was temporarily put out of action and "only" 103 pilots were lost. British fighter production, not counting repaired aircraft, produced 496 new aircraft in July, 467 in August, and 467 in September, covering the losses of August and September. Overy indicates the number of serviceable and total strength returns reveal an ''increase'' in fighters from 3 August to 7 September, 1,061 on strength and 708 serviceable to 1,161 on strength and 746 serviceable.<ref>{{harvnb|Overy|1980|pp=32–33}}</ref> Moreover, Overy points out that the number of RAF fighter pilots grew by one-third between June and August 1940. Personnel records show a constant supply of around 1,400 pilots in the crucial weeks of the battle. In the second half of September it reached 1,500. The shortfall of pilots was never above 10%. The Germans never had more than between 1,100 and 1,200 pilots, a deficiency of up to one-third. "If Fighter Command were 'the few', the German fighter pilots were fewer".<ref>{{harvnb|Overy|2001|p=38}}</ref>

Other scholars assert that this period was the most dangerous of all. In ''The Narrow Margin'', published in 1961, historians [[Derek Wood (author)|Derek Wood]] and [[Derek Dempster]] believed that the two weeks from 24 August to 6 September represented a real danger. According to them, from 24 August to 6 September 295 fighters had been totally destroyed and 171 badly damaged, against a total output of 269 new and repaired Spitfires and Hurricanes. They say that 103 pilots were killed or missing and 128 were wounded, a total wastage of 120 pilots per week out of a fighting strength of just under 1,000, and that during August no more than 260 fighter pilots were turned out by OTUs, while casualties were just over 300. A full squadron establishment was 26 pilots, whereas the average in August was 16. In their assessment, the RAF was losing the battle.<ref>{{harvnb|Wood|Dempster|2003|pp=212–213}}</ref> [[Denis Richards]], in his 1953 contribution to the official British account ''[[History of the Second World War]]'', agreed that lack of pilots, especially experienced ones, was the RAF's greatest problem. He states that between 8 and 18 August 154 RAF pilots were killed, severely wounded, or missing, while only 63 new pilots were trained. Availability of aircraft was also a serious issue. While its reserves during the Battle of Britain never declined to a half dozen planes as some later claimed, Richards describes 24 August to 6 September as the critical period because during these two weeks Germany destroyed far more aircraft through its attacks on 11 Group's southeast bases than Britain was producing. Three more weeks of such a pace would indeed have exhausted aircraft reserves. Germany had also suffered heavy losses of pilots and aircraft, hence its shift to night-time attacks in September. On 7 September RAF aircraft losses fell below British production and remained so until the end of the war.<ref>{{harvnb|Richards|1953|pp=176, 190–193}}</ref>

===Day and night attacks on London: start of the Blitz===
{{Main|The Blitz|Battle of Britain Day}}
[[File:Goering giving a speech to his fighter pilots near Calais September 1940.jpg|thumb|upright=1.5|Calais, September 1940. Göring giving a speech to pilots about the change in tactics: to bomb London instead of the airfields]]
Hitler's "Directive No. 17 – For the conduct of air and sea warfare against England" issued on 1 August 1940, reserved to himself the right to decide on terror attacks as measures of reprisal.<ref name="Dir 17" /> Hitler issued a directive that London was not to be bombed save on his sole instruction.<ref>{{harvnb|Korda|2010|p=198}}</ref> In preparation, detailed target plans under the code name [[The Blitz#Loge and Seeschlange|Operation Loge]] for raids on communications, power stations, armaments works and docks in the [[Port of London]] were distributed to the ''Fliegerkorps'' in July. The port areas were crowded next to residential housing and civilian casualties would be expected, but this would combine military and economic targets with indirect effects on morale. The strategy agreed on 6 August was for raids on military and economic targets in towns and cities to culminate in a major attack on London.{{sfn|Overy|2013|pp=84–85}} In mid-August, raids were made on targets on the outskirts of London.<ref name="19-24aug" />

Luftwaffe doctrine included the possibility of retaliatory attacks on cities, and since 11 May small-scale night raids by [[RAF Bomber Command]] had frequently bombed residential areas. The Germans assumed this was deliberate, and as the raids increased in frequency and scale the population grew impatient for measures of revenge.{{sfn|Overy|2013|pp=84–85}} On 25 August 1940, 81 bombers of Bomber Command were sent out to raid industrial and commercial targets in Berlin. Clouds prevented accurate identification and the bombs fell across the city, causing some casualties among the civilian population as well as damage to residential areas.<ref>{{harvnb|Wood|Dempster|2003|p=193}}</ref> Continuing RAF raids on Berlin led to Hitler withdrawing his directive on 30 August,<ref>{{harvnb|Bungay|2000|p=306}}</ref> and giving the go-ahead to the planned bombing offensive.{{sfn|Overy|2013|pp=84–85}} On 3 September Göring planned to bomb London daily, with General [[Albert Kesselring]]'s enthusiastic support, having received reports the average strength of RAF squadrons was down to five or seven fighters out of twelve and their airfields in the area were out of action. Hitler issued a directive on 5 September to attack cities including London.<ref>{{harvnb|Irving|1974|p=117}} Note: OKW War diary, 6–9 September 1940.</ref><ref>{{harvnb|Hough|Richards|2007|p=245}}</ref> In a widely publicised speech delivered on 4 September 1940, Hitler condemned the bombing of Berlin and presented the planned attacks on London as reprisals. The first daylight raid was titled ''Vergeltungsangriff'' (revenge attack).{{sfn|Overy|2013|p=83}}

[[File:London Blitz 791940.jpg|thumb|left|Smoke rising from fires in the London docks, following bombing on 7 September]]
On 7 September, a massive series of raids involving nearly four hundred bombers and more than six hundred fighters targeted docks in the East End of London, day and night. The RAF anticipated attacks on airfields, and 11 Group rose to meet them, in greater numbers than the Luftwaffe expected. The first official deployment of 12 Group's Leigh-Mallory's [[Big Wing]] took twenty minutes to form up, missing its intended target, but encountering another formation of bombers while still climbing. They returned, apologetic about their limited success, and blamed the delay on being scrambled too late.<ref name=7sept>Putland, Alan L. [http://www.battleofbritain1940.net/0036.html "7 September 1940."] {{Webarchive|url=https://web.archive.org/web/20100324160022/http://www.battleofbritain1940.net/0036.html |date=24 March 2010 }} ''Battle of Britain Historical Society''. Retrieved: 12 August 2009.</ref><ref>Putland, Alan L. [http://www.battleofbritain1940.net/0037.html "7 September 1940 – The Aftermath."] {{Webarchive|url=https://web.archive.org/web/20100130100131/http://www.battleofbritain1940.net/0037.html |date=30 January 2010 }} ''Battle of Britain Historical Society''. Retrieved: 12 August 2009.</ref>

The German press jubilantly announced that "one great cloud of smoke stretches tonight from the middle of London to the mouth of the Thames." Reports reflected the briefings given to crews before the raids – "Everyone knew about the last cowardly attacks on German cities, and thought about wives, mothers and children. And then came that word 'Vengeance!'" Pilots reported seeing ruined airfields as they flew towards London, appearances which gave intelligence reports the impression of devastated defences. Göring maintained that the RAF was close to defeat, making invasion feasible.{{sfn|Overy|2013|pp=83, 87}}

Fighter Command had been at its lowest ebb, short of men and machines, and the break from airfield attacks allowed them to recover. 11 Group had considerable success in breaking up daytime raids. 12 Group repeatedly disobeyed orders and failed to meet requests to protect 11 Group airfields, but their experiments with increasingly large Big Wings had some success. The Luftwaffe began to abandon their morning raids, with attacks on London starting late in the afternoon for fifty-seven consecutive nights.<ref name=8sept>Putland, Alan L. [http://www.battleofbritain1940.net/0038.html "8 September – 9 September 1940."] {{Webarchive|url=https://web.archive.org/web/20100324160027/http://www.battleofbritain1940.net/0038.html |date=24 March 2010 }} ''Battle of Britain Historical Society''. Retrieved: 12 August 2009.</ref>

[[File:Battle of britain firefighting.jpg|thumb|right|Members of the London Auxiliary Firefighting Service]]
The most damaging aspect to the Luftwaffe of targeting London was the increased distance. The Bf 109E escorts had a limited fuel capacity, giving them only a 660&nbsp;km (410-mile) maximum range solely on internal fuel,<ref>{{harvnb|Wagner|Nowarra|1971|p=229}}</ref> and when they arrived had only 10 minutes of flying time before turning for home, leaving the bombers undefended. Its eventual stablemate, the [[Focke-Wulf Fw 190]]A, was flying only in prototype form in mid-1940; the first 28 Fw 190s were not delivered until November 1940. The Fw 190A-1 had a maximum range of 940&nbsp;km (584 miles) on internal fuel, 40% greater than the Bf 109E.<ref>{{harvnb|Wagner|Nowarra|1971|p=235}}</ref> The [[Messerschmitt Bf 109]]E-7 corrected this deficiency by adding a ventral centre-line ordnance rack to take either an SC 250 bomb or a standard 300-litre Luftwaffe [[drop tank]] to double the range to 1,325&nbsp;km (820&nbsp;mi). The ordnance rack was not retrofitted to earlier Bf 109Es until October 1940.

On 14 September, Hitler chaired a meeting with the OKW staff. Göring was in France directing the decisive battle, so [[Erhard Milch]] deputised for him.<ref>{{harvnb|Irving|1974|p=117}}</ref> Hitler asked "Should we call it off altogether?" General [[Hans Jeschonnek]], Luftwaffe Chief of Staff, begged for a last chance to defeat the RAF and for permission to launch attacks on civilian residential areas to cause mass panic. Hitler refused the latter, perhaps unaware of how much damage had already been done to civilian targets. He reserved for himself the power to unleash the terror weapon. Instead, political will was to be broken by destroying the material infrastructure, the weapons industry, and stocks of fuel and food.

On 15 September, two massive waves of German attacks were decisively repulsed by the RAF by deploying every aircraft in 11 Group. Sixty German and twenty-six RAF aircraft were shot down. The action was the climax of the Battle of Britain.<ref name="Murray 1983, p. 52">{{harvnb|Murray|2002|p=52}}</ref>

Two days after this German defeat Hitler postponed preparations for the invasion of Britain. Henceforth, in the face of mounting losses in men, aircraft and the lack of adequate replacements, the Luftwaffe completed their gradual shift from daylight bomber raids and continued with nighttime bombing. 15 September is commemorated as [[Battle of Britain Day]].

===Night time Blitz, fighter-bomber day raids===
{{Main|The Blitz|Fighter-bomber attacks on the United Kingdom during World War II}}
[[File:Battle of britain air observer.jpg|thumb|[[Royal Observer Corps|Observer Corps]] spotter scans the skies of London.]]
At the 14 September OKW conference, Hitler acknowledged that the Luftwaffe had still not gained the air superiority needed for the [[Operation Sea Lion]] invasion. In agreement with [[Erich Raeder|Raeder]]'s written recommendation, Hitler said the campaign was to intensify regardless of invasion plans: "The decisive thing is the ceaseless continuation of air attacks." [[Hans Jeschonnek|Jeschonnek]] proposed attacking residential areas to cause "mass panic", but Hitler turned this down: he reserved to himself the option of terror bombing. British morale was to be broken by destroying infrastructure, armaments manufacturing, fuel and food stocks. On 16 September, Göring gave the order for this change in strategy.{{sfn|Overy|2001|pp=87–89}} This new phase was to be the first independent [[strategic bombing]] campaign, in hopes of a political success forcing the British to give up.{{sfn|Overy|2013|p=90}} Hitler hoped it might result in "eight million going mad" (referring to the population of London in 1940), which would "cause a catastrophe" for the British. In those circumstances, Hitler said, "even a small invasion might go a long way". Hitler was against cancelling the invasion as "the cancellation would reach the ears of the enemy and strengthen his resolve".{{refn|''Irving 1974, pp. 118–119'': Irving's sources were General [[Franz Halder]] and the OKW War Diary for 14 September 1940. [[Wilhelm Keitel|Keitel]]'s notes, ND 803-PS, record the same.|group=nb}}{{refn|Bungay refers to the 14 September meeting with Milch and Jeschonnek. Hitler wanted to keep up the "moral" pressure on the British Government, in the hope it would crack. Bungay indicates that Hitler had changed his mind from the day before, refusing to call off the invasion for the time being.<ref>{{harvnb|Bungay|2000|p=317}}</ref>|group=nb}} On 19 September, Hitler ordered a reduction in work on Operation Sea Lion.{{sfn|Overy|2001|p=88}} He doubted if strategic bombing could achieve its aims, but ending the air war would be an open admission of defeat. He had to maintain the appearance of concentration on defeating Britain, to conceal from [[Joseph Stalin]] his covert aim to [[Operation Barbarossa|invade the Soviet Union]].{{sfn|Overy|2013|p=91}}

Throughout the battle, most Luftwaffe bombing raids had been at night.{{sfn|Overy|2013|p=71}} They increasingly suffered unsustainable losses in daylight raids, and the last massive daytime attacks were on 15 September. A raid of 70 bombers on 18 September also suffered badly, and day raids were gradually phased out leaving the main attacks at night. Fighter Command still lacked any effective capacity to intercept night-time raiders. The [[night fighter]]s, mostly [[Bristol Blenheim|Blenheims]] and [[Bristol Beaufighter|Beaufighters]], at this time lacked airborne radar and so could not find the bombers. [[Anti-aircraft warfare|Anti-aircraft guns]] were diverted to London's defences, but had a much-reduced success rate against night attacks.{{sfn|Overy|2001|pp=78–89, 95–96}}

[[File:He 111 hit near Bristol in September 1940.jpg|thumb|A still from camera gun footage taken from a Supermarine Spitfire Mark I of No. 609 Squadron RAF attacking a Heinkel HE 111]]

From mid September, Luftwaffe daylight bombing was gradually taken over by [[Messerschmitt Bf 109 variants|Bf 109 fighters]], adapted to take one 250&nbsp;kg bomb. Small groups of fighter-bombers would carry out ''Störangriffe'' raids escorted by large escort formations of about 200 to 300 combat fighters. They flew at altitudes over {{convert|20000|ft|m}} where the Bf 109 had an advantage over RAF fighters, except the Spitfire.{{refn|group=nb|Jeffrey Quill wrote of his combat experience whilst flying with No. 65 Squadron: ''Nearly all our engagements with Me 109s took place at around 20,000 – 25,000 ft. The Spitfire had the edge over them in speed and climb, and particularly in turning circle. (...) One engagement with several Me 109s at about 25,000 ft over the Channel sticks in my memory...I was now convinced that the Spitfire Mk I could readily out-turn the 109, certainly in the 20,000 ft region and probably at all heights.''<ref name="spitfireperformance">{{cite web|url=http://www.spitfireperformance.com/65-quill-12aug40.jpg|title=Image: 65-quill-12aug40.jpg, (1000 × 1590 px)|website=spitfireperformance.com|access-date=28 November 2017}}</ref>}}{{refn|group=nb|Bf 109 leaking valves, supercharger faults/failure.<ref>Kesselring as cited in A. van Ishoven, Messerschmitt Bf 109 at War, (Ian Allan, Shepperton, 1977), p. 107.</ref>}}<ref>Steinhilper, op. cit., p.280,282, 295–297.</ref> The raids disturbed civilians, and continued the war of attrition against Fighter Command. The raids were intended to carry out precision bombing on military or economic targets, but it was hard to achieve sufficient accuracy with the single bomb. Sometimes, when attacked, the fighter-bombers had to jettison the bomb to function as fighters. The RAF was at a disadvantage and changed defensive tactics by introducing standing patrols of Spitfires at high altitude to monitor incoming raids. On a sighting, other patrols at lower altitude would fly up to join the battle.{{sfn|Overy|2001|pp=95–97}}{{sfn|Overy|2013|p=91}}

A Junkers Ju 88 returning from a raid on London was shot down in [[Kent]] on 27 September resulting in the [[Battle of Graveney Marsh]], the last action between British and foreign military forces on British mainland soil.<ref name="KO">Green, Ron and Mark Harrison. [https://web.archive.org/web/20141203142439/http://www.kentonline.co.uk/kent/news/forgotten-frontline-exhibition-t-a93111/ "Forgotten frontline exhibition tells how Luftwaffe fought with soldiers on Kent marshes."] ''Kent Online'', 30 September 2009. Retrieved: 21 August 2010.</ref>

German bombing of Britain reached its peak in October and November 1940. In post-war interrogation, [[Wilhelm Keitel]] described the aims as economic blockade, in conjunction with [[Battle of the Atlantic|submarine warfare]], and attrition of Britain's military and economic resources. The Luftwaffe wanted to achieve victory on its own and was reluctant to cooperate with the navy. Their strategy for the blockade was to destroy ports and storage facilities in towns and cities. Priorities were based on the pattern of trade and distribution, so for these months, London was the main target. In November their attention turned to other ports and industrial targets around Britain.{{sfn|Overy|2013|pp=90–93}}

Hitler postponed the Sealion invasion on 13 October "until the spring of 1941". It was not until Hitler's Directive 21 was issued, on 18 December 1940, that the threat to Britain of invasion finally ended.<ref name="Taylor and Mayer p.74"/>

During the battle, and for the rest of the war, an important factor in keeping public morale high was the continued presence in London of [[George VI|King George VI]] and his wife [[Queen Elizabeth The Queen Mother|Queen Elizabeth]]. When war broke out in 1939, the King and Queen decided to stay in London and not flee to Canada, as had been suggested.<ref group=nb>This proposal has since been confused, or conflated, with a possible flight by HMG in exile.</ref> George VI and Elizabeth officially stayed in [[Buckingham Palace]] throughout the war, although they often spent weekends at [[Windsor Castle]] to visit their daughters, Elizabeth (the future [[Elizabeth II|queen]]) and Margaret.<ref>[http://www.royal.gov.uk/textonly/Page4081.asp "George VI and Elizabeth during the war years."] UK: ''Royal government''. Retrieved: 30 June 2008.</ref> Buckingham Palace was damaged by bombs which landed in the grounds on 10 September and, on 13 September, more serious damage was caused by two bombs which destroyed the Royal Chapel. The royal couple were in a small sitting room about 80 yards from where the bombs exploded.<ref>{{harvnb|Ramsay|1988|p=90}}</ref><ref>{{harvnb|Churchill|1949|p=334}}</ref> On 24 September, in recognition of the bravery of civilians, King George VI inaugurated the award of the [[George Cross]].