The Blitz (English: 'lightning') was a bombing campaign by Nazi Germany and Fascist Italy against the United Kingdom during the Second World War. It lasted for eight months, from 7 September 1940 to 16 May 1941. The name is a shortened form of Blitzkrieg (English: "lightning war"), a term used in the popular press to describe a German style of surprise attack used during the war.
Toward the end of the Battle of Britain in 1940, daylight air superiority over the United Kingdom was contested between the Luftwaffe and the Royal Air Force. Germany began conducting mass air attacks against British cities, beginning with London, in an attempt to draw the RAF Fighter Command into a battle of annihilation. Adolf Hitler and Reichsmarschall Hermann Göring, commander-in-chief of the Luftwaffe, ordered the new policy on 6 September 1940. From 7 September 1940, London was systematically bombed by the Luftwaffe for 56 of the following 57 days and nights. The attacks included a large daylight attack against London on 15 September, a large raid on 29 December 1940 against London resulting in a firestorm known as the Second Great Fire of London, and a large raid on the night of 10–11 May 1941.
The Luftwaffe gradually decreased daylight operations in favour of night attacks to evade attacks by the RAF, and the Blitz became a night bombing campaign after October 1940. The Luftwaffe attacked the main Atlantic seaport of Liverpool in the Liverpool Blitz. The North Sea port of Hull, a convenient and easily found target or secondary target for bombers unable to locate their primary targets, suffered the Hull Blitz. The port cities of Bristol, Cardiff, Portsmouth, Plymouth, Southampton, Sunderland, Swansea, Belfast and Glasgow also were bombed, as were the industrial centres of Birmingham, Coventry, Manchester and Sheffield. More than 40,000 civilians were killed by Luftwaffe bombing during the war, almost half of them in the capital, where more than a million houses were destroyed or damaged.
In early July 1940, the German High Command began planning Operation Barbarossa, the invasion of the Soviet Union. Bombing failed to demoralise the British into surrender or do much damage to the war economy; eight months of bombing never seriously hampered British war production, which continued to increase. The greatest effect was to force the British to disperse the production of aircraft and spare parts. British wartime studies concluded that most cities took 10 to 15 days to recover when hit severely, although some, such as Birmingham, took three months.
The German air offensive and regime change operation failed because the Luftwaffe High Command (Oberkommando der Luftwaffe, OKL) did not develop a methodical strategy for destroying British war industry. Poor intelligence about British industry and economic efficiency led to the OKL concentrating on tactics, rather than strategy. The bombing effort was diluted by attacks against several sets of industries instead of constant pressure on those most vital to the British war effort.
Luftwaffe and strategic bombing
In the 1920s and 1930s airpower theorists such as Giulio Douhet and Billy Mitchell claimed that air forces could win wars, obviating the need for land and sea combat. It was thought that "the bomber will always get through", and could not be resisted, particularly at night. Industry, seats of government and communications could be destroyed, depriving an opponent of the means to make war. Bombing civilians would cause a collapse of morale, and a loss of production in the remaining factories. Democracies, where public opinion was allowed, were thought particularly vulnerable. The Royal Air Force (RAF) and the United States Army Air Corps (USAAC) adopted much of this apocalyptic thinking. The policy of RAF Bomber Command became an attempt to achieve victory through the destruction of civilian will, communications and industry.
The Luftwaffe took a cautious view of strategic bombing, but the OKL did not oppose the strategic bombardment of industries or cities. It believed it could greatly affect the balance of power on the battlefield by disrupting production and damaging civilian morale. OKL did not believe air power alone could be decisive, and the Luftwaffe did not adopt an official policy of the deliberate bombing of civilians until 1942.
The vital industries and transport centres that would be targeted for shutdown were valid military targets. It could be claimed civilians were not to be targeted directly, but the breakdown of production would affect their morale and will to fight. German legal scholars of the 1930s carefully worked out guidelines for what type of bombing was permissible under international law. While direct attacks against civilians were ruled out as "terror bombing", the concept of attacking vital war industries—and probable heavy civilian casualties and breakdown of civilian morale—was ruled as acceptable.
From the beginning of the Nazi regime until 1939, there was a debate in German military journals over the role of strategic bombardment, with some contributors arguing along the lines of the British and Americans. General Walther Wever (Chief of the Luftwaffe General Staff
1 March 1935 – 3 June 1936) championed strategic bombing, and the building of suitable aircraft, although he emphasised the importance of aviation in operational and tactical terms. Wever outlined five points of air strategy:
- To destroy the enemy air force by bombing its bases and aircraft factories, and defeat enemy air forces that attacked German targets.
- To prevent the movement of large enemy ground forces to the decisive areas, by destroying railways and roads, particularly bridges and tunnels, which are indispensable for the movement and supply of forces
- To support the operations of the army formations, independent of railways, i.e., armoured forces and motorised forces, by impeding the enemy's advance, and participating directly in ground operations.
- To support naval operations by attacking naval bases, protecting German naval bases and participating directly in naval battles
- To paralyse the enemy armed forces, by stopping production in armaments factories.
Wever argued that OKL should not be solely educated in tactical and operational matters, but also in grand strategy, war economics, armament production, and the mentality of potential opponents (also known as intelligence analysis). Wever's vision was not realised, staff studies in those subjects fell by the wayside, and the Air Academies focused on tactics, technology and operational planning, rather than on independent strategic air offensives.
In 1936 Wever died in an air crash, and the failure to implement his vision for the new Luftwaffe was largely attributable to his successors. Ex-army personnel, and his successors as Chief of the Luftwaffe General Staff, Albert Kesselring (3 June 1936 – 31 May 1937) and Hans-Jürgen Stumpff (1 June 1937 – 31 January 1939), are usually blamed for abandoning strategic planning for close air support.
Two prominent enthusiasts for ground-support operations (direct or indirect) were Hugo Sperrle, the commander of Luftflotte 3 (1 February 1939 – 23 August 1944), and Hans Jeschonnek, Chief of the Luftwaffe General Staff (1 February 1939 – 19 August 1943). The Luftwaffe was not pressed into ground support operations, either because of pressure from the army, or because it was led by ex-soldiers; indeed, the Luftwaffe favoured a model of joint inter-service operations, rather than independent strategic air campaigns.
Hitler, Göring, and air power
Hitler paid less attention to the bombing of opponents than to air defence, although he promoted the development of a bomber force in the 1930s, and understood it was possible to use bombers for strategic purposes. He told OKL in 1939 that ruthless employment of the Luftwaffe against the heart of the British will to resist, would follow when the moment was right. Hitler quickly developed scepticism toward strategic bombing, confirmed by the results of the Blitz. He frequently complained of the Luftwaffe's inability to damage industries sufficiently, saying, "The munitions industry cannot be impeded effectively by air raids ... usually, the prescribed targets are not hit".
While the war was being planned, Hitler never insisted upon the Luftwaffe planning a strategic bombing campaign, and did not even give ample warning to the air staff that war with Britain (or even Russia) was a possibility. The amount of firm operational and tactical preparation for a bombing campaign was minimal, largely because of the failure by Hitler, as supreme commander, to insist upon such a commitment.
Ultimately, Hitler was trapped within his own vision of bombing as a terror weapon (formed in the 1930s when he threatened smaller nations into accepting German rule, rather than suffering air bombardment). This had important implications. It showed the extent to which Hitler mistook Allied strategy for one of morale breaking, instead of one of economic warfare—and any damage to morale as a bonus.
Hitler was much more attracted to the political aspects of bombing. As the mere threat of it had produced diplomatic results in the 1930s, he expected that the threat of German retaliation would persuade the Allies to adopt a policy of moderation, and not to begin a policy of unrestricted bombing. His hope was—for reasons of political prestige within Germany itself—that the German population would be protected from the Allied bombings. When this proved impossible, he began to fear that popular feeling would turn against his regime, and redoubled efforts to mount a similar "terror offensive" against Britain, in order to produce a stalemate, in which both sides would hesitate to use bombing at all.
A major problem in the management of the Luftwaffe was Göring. Hitler believed the Luftwaffe was "the most effective strategic weapon", and in reply to repeated requests from the Kriegsmarine, for control over naval aircraft, he insisted, "We should never have been able to hold our own in this war, if we had not had an undivided Luftwaffe". Such principles made it much harder to integrate the air force into the overall strategy and produced in Göring a jealous and damaging defense of his "empire" while removing Hitler voluntarily from the systematic direction of the Luftwaffe at either the strategic or operational level.
When Hitler tried to intervene more in the running of the air force later in the war, he was faced with a political conflict of his own making, between himself and Göring, which was not fully resolved until the war was almost over. In 1940 and 1941, Göring's refusal to co-operate with the Kriegsmarine denied the entire Wehrmacht military forces of the Reich the chance to strangle British sea communications, which might have had a strategic, or decisive, effect in the war against the British Empire.
The deliberate separation of the Luftwaffe from the rest of the military structure encouraged the emergence of a major "communications gap" between Hitler and the Luftwaffe; other factors helped to exacerbate this. For one thing, Göring's fear of Hitler led him to falsify or misrepresent what information was available in the direction of an uncritical and over-optimistic interpretation of air strength. When Göring decided against continuing Wever's original heavy bomber programme, in 1937, the Reichsmarschall's own explanation was that Hitler wanted to know only how many bombers there were, and not how many engines each had. In July 1939 Göring arranged a display of the Luftwaffe's most advanced equipment at Rechlin, to give the impression the air force was more prepared for a strategic air war than was actually the case.
Battle of Britain
Although not specifically prepared to conduct independent strategic air operations against an opponent, the Luftwaffe was expected to do this over Britain. From July until September 1940 the Luftwaffe attacked Fighter Command, to gain air superiority as a prelude to invasion. This involved the bombing of English Channel convoys, ports, and RAF airfields and supporting industries. Destroying RAF Fighter Command was thought to allow the Germans control of the skies over the invasion area. It was supposed Bomber Command, Coastal Command, and the Royal Navy could not operate under conditions of German air superiority.
The weakness of the Luftwaffe's intelligence meant that their aircraft were too often unable to locate their targets, so that attacks on factories and airfields failed to achieve the desired results. British fighter aircraft production continued at a rate surpassing Germany's, during the Battle of Britain, by 2 to 1. The British produced 10,000 aircraft in 1940, in comparison to Germany's 8,000. The replacement of pilots and aircrew was more difficult. Both the RAF and Luftwaffe struggled to replace manpower losses (though the Germans had larger reserves of trained aircrew).
The circumstances hampered the Germans more than the British: Operating over home territory, British aircrew could fly again, if they survived being shot down. German crews (even if they survived) faced capture. Moreover, the Reich's bombers carried four to five crew, representing a greater loss of manpower. On 7 September the Germans shifted away from the destruction of the RAF's supporting structures. German intelligence suggested Fighter Command was weakening, and that an attack on London would force it into a final battle of annihilation, while compelling the British Government into surrender.
The decision to change strategy is sometimes claimed to have been a major mistake by OKL, argued that persisting with attacks on RAF airfields might have won air superiority for the Luftwaffe. Others argue that the Luftwaffe made little impression on Fighter Command, in the last week of August and first week of September, and that the shift in strategy was not decisive. It also has been argued that it was doubtful the Luftwaffe could have won air superiority, before the "weather window" began to deteriorate (in October).
It also was possible, if RAF losses became severe, that they could pull out to the north, wait for the German invasion, then redeploy southward again. Other historians argue that the outcome of the air battle was irrelevant; the massive numerical superiority of British naval forces and the inherent weakness of the Kriegsmarine would have made the projected German invasion, Unternehmen Seelöwe (Operation Sea Lion), a disaster, with or without German air superiority.
Change in strategy
Regardless of the ability of the Luftwaffe to win air superiority, Hitler was frustrated by its slow advance. With no sign of the RAF weakening, and the Luftflotten suffering many losses, OKL was keen for a change in strategy. To reduce losses further, strategy changed to prefer night raids, darkness offering the bombers greater protection.