# Operation Adler

Operation Adler was the code name designated by the Luftwaffe for their air offensive against Great Britain in the summer of 1940. The defensive side of this operation was known as the Battle of Britain. This offensive was part of an ambitious campaign, namely the amphibious invasion of England. The Luftwaffe bore the responsibility of neutralizing the Royal Air Force (RAF) and its capability to thwart the planned invasion. Operational planners were tasked with developing a plan to systematically destroy Great Britain's ability to wage war. This strategic air offensive was only one part of the overall campaign for the eventual invasion of England. The first step in this operation would be attaining air superiority for the invading force. Hermann Göring, the Luftwaffe Commander, violated all seven 'principles of war' as stated in U.S. Army Manual FM 100-5, but still came very close to defeating the RAF. The Luftwaffe's targeting of London was seen by the British as a fatal mistake. Adlertag (Eagle Day) was the Goring designated code name for the first day of German offensive air operations aimed at destroying the RAF.

## Adlertag

Adlertag ("Eagle Day") was the first day of Unternehmen Adlerangriff ("Operation Eagle Attack"), an air operation by Nazi Germany's Luftwaffe (German air force) intended to destroy the British Royal Air Force (RAF). The operation came during the Battle of Britain after Britain rejected all overtures for a negotiated peace with Germany. However, Adlertag and subsequent operations failed to destroy the RAF or gain local air superiority.
On 16 July 1940 Hitler gave the German armed forces (Wehrmacht) a directive (Directive No. 16) that ordered provisional preparations for invasion of Britain. This operation was codenamed Operation Sea Lion (Unternehmen Seelöwe). Before this could be carried out, air superiority or air supremacy was required. The Luftwaffe was to destroy the RAF in order to prevent it from attacking the invasion fleet or providing protection for the Royal Navy's Home Fleet, which might attempt to prevent a landing by sea. On 1 August Hitler gave the Luftwaffe's commander-in-chief, Reichsmarschall Hermann Göring and the Oberkommando der Luftwaffe Directive No. 17 ("or the conduct of air and sea warfare against England") to launch the air assault.
The essential target was RAF Fighter Command. The service's destruction would deny the British their air superiority asset and feeling vulnerable to air attack might negotiate for peace. Throughout July and early August, the Germans made preparations for Adlertag. The date of the assault was postponed several times because of bad weather. Eventually, it was carried out on 13 August 1940. The German attacks on 13 August inflicted significant damage and casualties on the ground, but, marred by poor intelligence and communication, they did not make a significant impression on Fighter Command's ability to defend British air space.

## Battle of Britain

The failure of Adlertag did not deter the Luftwaffe from continuing its campaign. The assault against RAF airfields continued throughout August and into September 1940. The battles involved large numbers of aircraft and heavy losses on both sides. The Luftwaffe failed to develop any focused strategy for defeating RAF Fighter Command. At first, it attempted to destroy RAF bases, then switched to strategic bombing by day and night. It tried to achieve the destruction of several British industries at the same time, switching from bombing aircraft factories, to attacking supporting industries, import or distribution networks such as coastal ports. An attempt was even made against unrelated targets, such as destroying the morale of the British population.
The failure of the Luftwaffe to identify the radar chain and distinguish RAF fighter bases from those of other RAF commands undermined its ability to destroy the British fighter defences. The Luftwaffe underestimated British radar, and they had not realised its importance in the British operational system. To the contrary, OKL believed that the radar stations would benefit the German effort by sending RAF forces into large-scale air battles for the Luftwaffe to decimate. The RAF aircraft industry supported the losses and its pilots were replaced sufficiently to limit the RAF's decline in strength and deny the Germans victory. Conversely, the RAF were able to ensure the serviceability rates and aircrew numbers of the Luftwaffe declined in August–September.