|Part of the
|Commanders and leaders|
|Casualties and losses|
–43,000 civilians dead,
 ~46,000 injured
figures for wounded possibly as high as 139,000 
2,265 aircraft (Summer 1940 – May 1941) 
The Blitz was a German bombing offensive against Britain in 1940 and 1941, during the
The Luftwaffe gradually decreased daylight operations in favour of night attacks to evade attack by the RAF, and the Blitz became a night bombing campaign after October 1940. The Luftwaffe attacked the main
In early July 1940 the German High Command began planning
The German air offensive failed because the Luftwaffe High Command (
In the 1920s and 1930s,
The Luftwaffe took a cautious view of strategic bombing and OKL did not oppose the strategic bombardment of industries or cities and 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 have a policy of systematic "terror bombing". (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
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
In 1936, Wever was killed 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,
Hitler paid less attention to the bombing of opponents than 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 interfered with 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 submit to air bombardment. This fact had important implications. It showed the extent to which Hitler personally mistook Allied strategy for one of morale breaking instead of one of
A major problem in the managing of the Luftwaffe was Göring; Hitler believed the Luftwaffe was "the most effective strategic weapon", and in reply to repeated requests from the
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, which other factors helped to exacerbate. 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
Although not specifically prepared to conduct independent strategic air operations against an opponent, the Luftwaffe was expected to do so 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
The Luftwaffe's poor intelligence meant that their aircraft were not always able to locate their targets, and thus attacks on factories and airfields failed to achieve the desired results. British fighter aircraft production continued at a rate surpassing Germany's 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 affected 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, bombers had four to five crewmen on board, 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 an attack on London would force it into a final battle of annihilation while compelling the
The decision to change strategy is sometimes claimed as a major mistake by OKL. It is 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 has also been argued that it was doubtful the Luftwaffe could have won air superiority before the "weather window" began to deteriorate in October.
 It was also 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,
Regardless of the ability of the Luftwaffe to win air superiority, Hitler was frustrated it was not happening quickly enough. 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, giving the bombers greater protection under cover of darkness.  [a]
It was decided to focus on bombing Britain's industrial cities, in daylight to begin with. The main focus was London. The first major raid took place on 7 September. On 15 September, on a date known as Battle of Britain Day, a large-scale raid was launched in daylight, but suffered significant loss for no lasting gain. Although there were a few large air battles fought in daylight later in the month and into October, the Luftwaffe switched its main effort to night attacks. This became official policy on 7 October. The air campaign soon got under way against London and other British cities. However, the Luftwaffe faced limitations. Its aircraft—
Although it had equipment capable of doing serious damage, the Luftwaffe had unclear strategy and poor intelligence. OKL had not been informed that Britain was to be considered a potential opponent until early 1938. It had no time to gather reliable intelligence on Britain's industries. Moreover, OKL could not settle on an appropriate strategy. German planners had to decide whether the Luftwaffe should deliver the weight of its attacks against a specific segment of British industry such as aircraft factories, or against a system of interrelated industries such as Britain's import and distribution network, or even in a blow aimed at breaking the morale of the British population.  The Luftwaffe's strategy became increasingly aimless over the winter of 1940–1941.  Disputes among OKL staff revolved more around tactics than strategy.  This method condemned the offensive over Britain to failure before it began. 
In an operational capacity, limitations in weapons technology and quick British reactions were making it more difficult to achieve strategic effect. Attacking ports, shipping and imports as well as disrupting rail traffic in the surrounding areas, especially the distribution of coal, an important fuel in all industrial economies of the Second World War, would net a positive result. However, the use of