THE BATTLE OF BRITAIN
JULY–AUGUST 1940
Between mid-April and mid-June the Luftwaffe concentrated on the immense and fateful combined arms campaigns fought out across northwest Europe, from Denmark and Norway through the Low Countries, to the Channel coast and the Isle de France. Air operations against Britain were limited to high-altitude, high-speed daylight reconnaissance flights, and nighttime harassment raids by a few dozen bombers ranging widely across British airspace in Staffeln (flights of 6–12), in pairs, or even singly.
Nor did the Franco-German Armistice lead to an immediate increase in the tempo of Luftwaffe operations against Britain. For one thing, the Luftwaffe suffered significant attrition in its Weserübung and Fall Gelb operations, and like its British antagonist, needed recovery time. Moreover, until Hitler decided what do next, the German armed forces (Wehrmacht) could not begin serious planning for further operations.1
Although, beginning as early as the Sudetenland crisis of 1938, Luftwaffe and Kriegsmarine (navy) staff officers had studied the problems of air and naval operations against the United Kingdom, they had prepared no detailed contingency plans. In the absence of direction or guidance on the subject from Hitler,2 the Armed Forces High Command (Oberkommando der Wehrmacht, or OKW) failed to produce even an outline strategic concept of operations against Britain until the end of June, when Generalmajor Alfred Jodl, OKW chief of operations, delivered an analysis of Germany’s strategic options in the event that the British refused to concede defeat. As Jodl saw it, Germany could pursue a maritime strategy aimed at severing economic and strategic arteries of the British Empire; launch an all-out strategic air offensive against Britain itself; or, “as a last resort,” invade the British Isles with ground forces. That same day, Göring issued to the Luftwaffe a directive concerning operations against Britain.3
Göring’s initial campaign directive straddled Jodl’s first two options and ignored the third, probably as a consequence of Hitler’s unwillingness to choose. The Luftwaffe C in C not only failed to secure from his leader a decision on the fundamental, strategic choice, but shuffled off onto his air-fleet commanders and their staffs the task of working out detailed plans. As a natural consequence, Luftflotte (Air Fleet) 2 under Albert Kesselring and Luftflotte 3 under Hugo Sperrle developed different concepts of operations.4
Across the Channel, Dowding was standing by his 1937 assessment that the Luftwaffe had a choice of two concepts for air operations against Britain: either concentrate all their forces on a chosen point of attack in an attempt to win a decisive battle, or spread their attacks across a wide front, in hopes of wearing down British defenses by attrition. It appears, however, that in the first weeks after the French collapse, most British leaders feared an immediate invasion more than the prospect of a sustained, strategic air offensive by the Luftwaffe. Intelligence initially evaluated Luftwaffe attacks on ports as precursors to invasion, although a more accurate estimate of German intentions quickly emerged. Ironically, the offensive option most Britons feared most was the option least favored by the enemy; no one on the German side, neither army, navy, air force, nor the political leader, really wanted to force the issue with a Channel crossing.5
Making hasty logistical preparations for operations against Great Britain during the second half of June and the first half of July, the Luftwaffe also gradually expanded the scale of its night attacks. Even these initial, low-intensity night attacks were enough to unnerve some British leaders. In the prime minister’s private office, Colville recorded, “the night-bombing is unexpectedly accurate and anti-aircraft fire extraordinarily ineffective.” Major daylight operations did not begin until the second week in July. At that point, the principal Luftwaffe strike forces, Luftflotte 2 and Luftflotte 3, began steadily intensifying attacks aimed at gaining and exploiting air superiority over the Channel and probing British air defenses inland, while logistical preparations for an all-out, strategic air offensive (designated Adlerangriff, “Eagle Offensive”) continued. It was this sudden, sharp upturn in the tempo of these operations from July 10 that Dowding and the Air Ministry later identified, fairly arbitrarily, as marking the commencement of the Battle of Britain.6
In the fighting that Luftwaffe airmen referred to as the Kanalkampf (Battle of the Channel), the Germans enjoyed considerable operational advantages. Over the channel, the Luftwaffe held the initiative at the strategic, operational, and tactical levels, and therefore could concentrate forces for attacks at times and places of their choosing. The geography of the theater of operations allowed them to assemble large formations outside the effective range of British radar, and then dash in to attack. Fighting mostly over water, at roughly equal distances from the relevant British and German bases, effectively neutralized two of Fighter Command’s key advantages: radar warning time, and the chances of capturing German aircrew downed on British soil. Oddly, the Wehrmacht proved better prepared than the British armed forces for maritime combat search and rescue (CSAR).7
From Dowding’s point of view the Channel fighting involved risks and costs disproportionately greater than what he perceived to be a strategically marginal issue. In fact, the Channel operations might well have been a German feint, designed to lure Fighter Command away from its carefully prepared battle space and divert defenders from more important targets inland. Moreover, at this time Dowding’s relatively inexperienced sector controllers frequently underestimated both the numbers of aircraft in the German formations, and their altitudes. The latter was a serious failing: Fighter Command expected to fight against the odds, but allowing enemy fighters to “bounce” British aircraft (dive on them from above) handed the enemy a lethal advantage. The key to survival and success in air combat was to structure the engagement as a hunt, not a duel, taking the enemy by surprise and at a positional disadvantage. In combat over the Channel, Fighter Command was not well positioned to control the structure of the engagements.8
Characteristically, Churchill’s reaction to the sudden rise in the Luftwaffe tempo of operations was to head for Dover to observe the battle. Finding nothing to see there on July 11, next day the prime minister visited RAF Kenley to inspect a Hurricane squadron, then invited Dowding to visit him at Chequers on Saturday the thirteenth. Dowding briefed Churchill, who already was carefully following overall RAF losses and claims, regarding fighter aircraft performance (high on the Hurricane, down on the Defiant) and updated the prime minister on countermeasures against the enemy navigational beam Knickebein (British code-name “Headache”). Dowding also discussed his personal headache: the pending retirement the Air Ministry continued to hold over him. Presumably, he came away reassured by the same unqualified support that the prime minster had already communicated to Sinclair and the Air Ministry.
Despite demonstrably appreciating the importance of cultivating the prime minister’s confidence, Dowding never hesitated to deliver bad news, when the news was bad. On July 16, Dowding reported personally—and negatively—on the prospects for quick answers to the night-bombing threat. The ever-observant Colville, highly sensitive to Churchill’s moods, recorded that Dowding’s report was “rather depressing.” As the scale of Luftwaffe attacks ramped up during July, there was widespread concern, which Churchill and Dowding shared, about the growing strain on civilian morale. Moreover, direct protection of aircraft factories was thought necessary to sustain the output of fighter aircraft needed to win the battle for air superiority. Yet despite strong and recurring pressure from the Air Staff and even the prime minister, Dowding resisted redeploying fighters to provide point defense for factories, persuading Churchill that the technically correct solution was the development of radar-controlled AAA batteries.9
During the second half of July, the Luftwaffe repeatedly bombed historic and picturesque coastal towns including Falmouth, Plymouth, Portland, and Weymouth, as well as the important naval base at Dover. The outcomes of the resulting aerial combat fluctuated as sharply as the notoriously treacherous Channel currents. July 19 was a “disaster” for the British fighters, with ten lost against only four enemy planes downed. This unusually negative “score” was made worse for Fighter Command by the fact that seven of the ten losses were suffered by a single unit, 141 Squadron, which was operating the two-seat, gun-turret equipped, Boulton Paul Defiant as a “heavy” fighter. Twelve aircrew from 141 Squadron perished, and the squadron had to be temporarily withdrawn from combat. The Air Ministry had placed high hopes on the Defiant, but now was forced to recognize that, like the Luftwaffe’s long-range Me 110 Zerstörer, it was incapable of daylight, air-to-air combat against single-seat, air-superiority fighters.
Fighter Command fared much better on July 20, however, successfully coordinating elements of four squadrons to repulse an attack by fighter-escorted Stuka dive bombers on Convoy “BOSOM.” In this case, Park anticipated the German attack, and 11 Group controllers were able to preposition the British interceptors for maximum effect despite some rather eccentric maneuvers by a fifth squadron, the notoriously nonconformist 601 “City of London” Squadron, whose flight leader somehow gained the impression that controllers wanted his aircraft to orbit over a village pub some miles inland. As was becoming typical, the air-to-air “score” on the twentieth was roughly even. The circumstances surrounding the defense of Convoy “BOSOM” appear to have inspired British leaders to consider the possibility of manipulating convoy movements in an effort to turn the tables on the Luftwaffe, and secure for Fighter Command an element of tactical initiative in the air and sea Battle of the Channel.
On July 25, Luftflotte 2 combined with Kriegsmarine E-Boats to overwhelm the RAF fighters and Royal Navy destroyers attempting to protect Convoy CW 8, sinking five merchant vessels and damaging two destroyers. Next day, the Admiralty halted daylight merchant-ship movements through the Channel. The Luftwaffe’s cumulative effect on Channel shipping during July was sufficiently serious to focus on the problem the attention of the prime minister and the Cabinet Defence Committee, who summoned Dowding and Vice-Chief of Air Staff Peirse to a July 26 discussion. After another damaging attack on shipping and the port of Dover on July 27, the Defence Committee again considered the matter. Dover’s importance as a base for a Royal Navy counterattack on a potential German invasion force inspired suggestions that Fighter Command should deploy more aircraft to stations near the southeast coast; there was even a proposal for an attack on the German bases in the Pas de Calais using Fighter Command assets.10
Once again under pressure from Whitehall, Dowding decided to order only limited redeployments. The Admiralty, however, like Dowding, was inclined to cut its losses, in order to preserve its rapidly dwindling destroyer force for use against the expected German amphibious invasion, which the navy believed would be the decisive battle in the defense of Great Britain. On July 29, therefore, the Royal Navy revised its position regarding Dover, redeploying its anti-invasion destroyer forces north to Harwich and Sheerness. The apparently deciding factor was intelligence that Dover would soon be within range of German siege artillery being mounted at Calais. Forcing the Royal Navy to abandon a principal operating base, its best base for close-in, counterinvasion operations, was a significant accomplishment for the Wehrmacht. The strategic gain in neutralizing Dover as a naval base was offset, however, by the tactical relief afforded Fighter Command, which made the Luftwaffe’s task of gaining air superiority more difficult.11
The opposing, operational-level air commanders spent the first week of August tinkering with the postures of their forces and worrying about the weather. Dowding not only tracked the raw numbers of aircraft and pilots lost, but personally controlled deployment and redeployment of his squadrons, rotating tired or hard-hit units north to 12 Group, and replacing them with fresh—or at least, fresher—squadrons. Throughout, Dowding refused to increase the numbers in 11 Group at the expense of 12 Group. Indeed, less than 25 percent of Fighter Command’s strength had been fully engaged in the fighting over the Channel at any one time. As a result of Dowding’s insistence upon carefully conserving his forces, Fighter Command actually gained strength during July.12
The Luftwaffe was also attempting to learn from the fighting over the Channel, and ready itself for Adlerangriff. Göring’s instructions defining Fighter Command’s radar and communications facilities as first-priority targets show that he had understood at least one key point. The Reichsmarschall’s main concern, however, was the limited range and endurance of his high-performance, Messerschmidt (Me.) 109 fighters. His order to the fighters to refrain from chasing individual enemy interceptors was primarily intended to ensure efficient use of their limited time in the combat airspace; contrary to legend, Göring did not at this point order the fighters to confine themselves to close escort of the bomber formations. Copying the German army’s well-known technique of war gaming a prospective operation, senior officers from the air fleets tested their operational concepts in early August, but the usefulness of the exercises probably was negated by the continued underestimation by Luftwaffe intelligence of both Fighter Command’s strength and—astonishingly—the effectiveness of its IAD system.13
Before the Germans could begin Adlerangriff, a British attempt to sneak a convoy code-named “PEEWIT” through the Straits of Dover during the night of August 7 provoked intense fighting on the eighth. Churchill had been pressing since late July for a change in strategy, diverting important cargoes to safer routes and treating Channel convoys as “a tactical operation.” Service advisers to the War Cabinet Defence Committee, Pound for the navy and Peirse for the air force, now decided that the coastal shipping losses were tolerable—although further destroyer losses were another matter. If the British goal was to lure the Germans, especially the vulnerable Junkers’ Ju-87 Stuka dive bombers, into a trap, Fighter Command’s first effort to spring it failed to produce a decisive concentration of force. Only the Hurricanes of No. 145 Squadron successfully intercepted the initial attack, ten Stukas escorted by twenty Me. 109s, that Sperrle’s Luftflotte 3 launched against convoy PEEWIT.
Against a loss of two “Hurricanes” and pilots, No. 145 Squadron claimed to have downed six of the dive bombers and three enemy fighters, while preventing any loss to the convoy from air attack. Sperrle persisted, however, and at midday struck convoy PEEWIT with a force of thirty dive bombers escorted by more than sixty fighters. Fighter Command’s controllers successfully positioned elements of five fighter squadrons to intercept, but the German fighters succeeded in drawing them away from the attacking Stukas, which were therefore free to sink four of the convoy and damage six or seven other vessels. A series of further attacks throughout the afternoon, in strengths ranging from fifteen to nearly a hundred, provoked intense air-to-air combat, but resulted in no further losses to the convoy. Still, combined with the losses inflicted the previous night in surface attacks by Kriegsmarine E-boats, Luftflotte 3 had practically destroyed convoy PEEWIT.
An Air Ministry narrative later praised the single-handed defense of convoy PEEWIT by No. 145 Squadron on the morning of August 8 as “a splendid example of . . . a determined squadron,” and indeed the action seemed so singular that the prime minister, seconded by the secretary of state for air and by Air Vice-Marshal His Royal Highness the Duke of Gloucester, directed Dowding to commend No. 145 Squadron in the name of the War Cabinet. The prime minister’s attitude toward the Battle of the Channel was oddly inconsistent. On the one hand, he was sentimental about the sinking of “those poor little ships” plying the coastal waters; on the other hand, convinced that Fighter Command was winning the air battles over the narrow seas by overwhelming margins, he was fully prepared to use convoys as bait. As he admitted to Colville, however, “the surviving bait are getting a bit fed up.”14
The action over convoy PEEWIT climaxed the first phase of the campaign. It was also, in a number of ways, characteristic. British shipping losses had been substantial, but far from mortal. The same was true of their aircraft losses, although pilot losses gave more reason for concern. Fighter Command’s overall “kill” ratio of roughly 1.5:1 was not as nearly as satisfactory as the 4:1 or 5:1 the British thought it was, but it was sufficient at least to put equal strain on the German aviators.15 In light of the German objective for the first phase of their operations to gain local air superiority over the Channel, their operations achieved at best only partial success, at considerable cost. They did make it too expensive for the British to continue using some important ports and some coastal supply lines, but the Luftwaffe’s ability to operate in the associated airspace continued to be bitterly contested.16
Hitler’s Directive 17 called for the decisive air-superiority battle to begin on or after August 5. Luftwaffe planners expected to win this battle in four days. Unfavorable weather repeatedly postponed the start date, code-named Adlertag (Eagle Day). Adlertag finally fell on August 13, which seemed likely to begin a stretch of good weather. When a break in the weather two days earlier gave Kesselring and Sperrle the opportunity to resume large-scale operations, for some reason they decided to return to attacks on targets in the Channel and along the south coast of England. The resulting intense engagements proved costly in personnel to both sides, with Churchill “very excited” by the claims of Fighter Command’s pilots. In fact, the thirty-eight kills they claimed was exactly double the losses they actually inflicted on the attackers. “Jock” Colville’s diary and other first-person evidence make it clear, however, that at this stage even the inner circle of the Government was accepting RAF claims at face value.17
The final preliminary to Adlerangriff took place on August 12, when in accordance with Göring’s operational concept, a well-planned series of attacks targeted Chain Home and Chain Low radar stations in key locations. The early morning strikes obtained surprise, and yielded excellent bombing accuracy. Despite heavy damage to several installations, however, every station was either back in service or replaced by temporary work-arounds within hours. Luftwaffe intelligence, while accurately identifying the radar stations and appreciating their importance, had incorrectly analyzed how the Fighter Command IAD system actually functioned, and therefore underestimated its flexibility and resiliency. Given the technological limitations of intelligence gathering and weaponry at the time, it was in any case up to almost random chance whether or not even sustained attacks would destroy the sector control rooms or interrupt the stations’ electrical power and telephone communications, which were the critical elements of the system. Most importantly, the Luftwaffe leadership failed to comprehend the persistence in attack necessary to trigger system collapse.
On the morning of August 13, the Luftwaffe finally set out to deliver the so-long-awaited knockout blow, but the famous variability of the English weather combined with indecisive exercise of personal command by Göring to create a muddle. As Adlertag wore on, raids appeared in the skies of southern England one after the other, seemingly uncoordinated. Luftwaffe losses mounted, culminating in the “massacre” of an entire Staffel of Ju-87 Stukas. The overall result of the day’s air-to-air combat was one of the most one-sided of the entire campaign: Fighter Command downed forty-seven German aircraft against a loss of thirteen. If the British pilots, out of the chaos of battle, distorted the after-action assessments by claiming seventy-eight kills, the Germans began an (ultimately) highly damaging spiral of delusion by adding dozens of imaginary shoot-downs to the admittedly large number of British aircraft destroyed on the ground, for a grossly exaggerated total of eighty-four.18
Despite the German airmen’s gaudy claims, all ranks in the Luftwaffe were aware that Adlerangriff had proved—at best—an expensive sort of success, and at worst, a costly fiasco. The Luftwaffe leadership would have been depressed, rather than merely frustrated, had it known the reaction of their British opponents: “The question everyone is asking today,” Colville wrote, “is what is the motive of these gigantic daylight raids, which cost so much and effect so little?” As the day’s favorable kill rate demonstrated, massed, daylight attacks played into Dowding’s hands. He was hoping that the Germans would impale themselves on his defenses. Even after he mentally discounted by 20–25 percent his pilot’s claims from August 13, the results elated him. Characteristically, however, he reacted with redoubled attention to detail, devoting the fourteenth to carefully reshuffling his squadrons just in time to meet the Luftwaffe’s greatest effort yet.19
The August 15 action began with relatively small-scale probing attacks on British defenses and air bases in Kent, apparently intended to distract attention from the first—and as things turned out, the last—major daylight attack on Britain by Luftflotte 5. Flying from Stavanger in southern Norway, seventy-plus He 111 medium bombers were escorted by twenty-plus Me. 110-D long-range fighters, and followed from Aalborg in northern Denmark by at least sixty of the fast Ju-88 strike aircraft, half configured as C-model heavy fighters; all targeted No. 12 Group bases in the north of England. Rested and alert squadrons from both 12 Group and 13 Group heavily attacked both strike forces, and in the absence of the Luftwaffe’s air-superiority fighter, the short-range Me. 109, Luftflotte 5 lost twenty-four aircraft while inflicting only minor damage and no kills on the British interceptors. Unsurprisingly in the circumstances, Luftflotte 5’s target identification and bombing accuracy were poor.
Churchill, “consumed with excitement” as the reports of enemy aircraft destroyed mounted, now drove to Fighter Command HQ to watch the battle continue to unfold on Dowding’s own plotting table. Throughout the afternoon of August 15, Luftflotte 2 and Luftflotte 3 launched sustained attacks on the 11 Group sectors in southeastern England. These attacks, utilizing strike forces of different sizes, composed of different types of aircraft, employing different tactics, and engaging a wide variety of targets, nearly overwhelmed 11 Group’s controllers with the sheer complexity of the defense problem. Despite some early afternoon successes for the Luftwaffe, however, the pendulum of battle swung back again in midafternoon, when No. 601 Squadron wiped out a Staffel of Ju-88s; in the late afternoon, three squadrons, Nos. 234, 213, and 87, downed 13 Me. 110s from the beleaguered heavy fighter wing ZG 76, whose 1 Group had been destroyed in the northern operation that morning.
Perhaps the worst blow to the Luftwaffe of an already historically bad day was the last. In the evening, No. 111 Squadron and No. 32 Squadron combined to decimate Erprobungsgruppe (Test Wing) 210, which during the preceding weeks had been the most effective of all the Luftwaffe strike forces in operations against Britain. Specializing in low-altitude, high-speed attacks by specially configured Me. 109 and Me. 110 fighter bombers, the missions flown by Erpro 210 were difficult to track, frequently achieved surprise, and had probably done more serious damage to Fighter Command’s IAD system than all the rest of the Luftwaffe bombing combined. Moreover, Erpro 210’s fighter-bombers came closer to realizing the airpower zealots’ vision of a self-defending bomber formation than any other type then operational. Erpro 210’s costly failure in its third raid on the fifteenth suggests that the combat effectiveness of the attacking Germans may have been wearing down faster than that of the defending Britons.20
Altogether, the Luftwaffe lost 75 aircraft on something over 2,000 sorties, its highest sortie total of any single day in the entire campaign. This amounted to a painful, but not necessarily unsustainable loss rate of almost 4 percent. The British lost 34 fighters, but with claims of 182 “kills,” believed they had won a victory of monumental proportions. In his postwar account, Churchill implied that this action in the North had been, in at least a limited sense, strategically decisive. “Henceforth,” he observed, “everything north of the Wash was safe by day.” Why, therefore, did Dowding maintain the relative strengths of his groups essentially unchanged after the fifteenth? Numerous critics have alleged that stubborn inflexibility led him to over-insure against a threat that, never great, had now practically vanished. Shifting more squadrons to 11 Group sooner would have at least slightly improved odds that were to rise as high as 1:10 against the interceptors at points of attack.
Dowding’s insistence on maintaining the balance of relative strengths that he had established among 13, 12, and 11 Groups rested on more, however, than simply the defense of Scotland and the north of England. His primary motive was to hold a strategic reserve of squadrons apart from the fighting in the southeast.21 Throughout the 1940 campaign, the shadows of the Somme lay on him. His concept of operations was based on the Fabian strategy of endurance, fighting a protracted series of limited engagements; a middle course between gambling on winning an early, decisive battle of annihilation, on the one hand, or slogging through a campaign of annihilation by attrition, on the other. Dowding preferred to gamble that he could limit Fighter Command’s attrition to losses that it could sustain indefinitely, and thereby frustrate Hitler’s strategic purposes. Although this operational strategy has been adversely criticized as “conservative” and overly cautious, in fact it represented a daring exercise in calculated risk-taking.
Dowding deliberately left high-value targets such as airfields and aircraft factories exposed to potential attack in order to preclude catastrophic, short-term losses to the fighter force. The counterproductive effort to avoid all risk, the chimerical attempt to be strong everywhere, are hallmarks of mediocre generalship; the essence of Dowding’s operational strategy was just the opposite. He traded the day-to-day, hour-by-hour tactical risks of engaging less than his maximum strength for the ultimate, strategic gain of denying the enemy a “decisive battle” for air superiority. The strength of will to adhere to this decision under almost unimaginable pressure truly was, as Churchill put it, “an example genius in the art of war.”22
Accepting that Dowding’s strategic judgment surpassed that of his critics, nevertheless the aftermath of the August 15 battles calls into question his practice of command. By some accounts Leigh-Mallory was “furious” at the limited role played by 12 Group’s fighters. David Fisher has implied that Dowding was unable to focus his attention on the deteriorating command relationships because he was becoming emotionally overwrought by the slaughter of his fighter pilots. While it is clearly true that Dowding remained indefensibly, if not inexplicably, tolerant of Leigh-Mallory’s behavior, Fisher’s suggestion of emotional breakdown lacks credibility. During late August and early September the AOC-in-C carefully studied pilot readiness on a squadron-by-squadron basis, assessing the squadrons’ condition in minute detail. Dowding’s command focus on his pilots—not only their survival rates, but also their physical and psychological fitness—was altogether rational. Long before Churchill, Dowding had realized that the outcome of the campaign was in the hands of “the Few.”23