Adlertag - "Eagle Day"

13 August 1940

Operation Eagle Attack

Adlertag ("Eagle Day") was the first day of Unternehmen Adlerangriff ("Operation Eagle Attack"), the codename for a Luftwaffe (German air force) military operation to destroy the British Royal Air Force (RAF).


After Western Europe had been neutralised, the German High Command turned their attention to Britain, which had become the Allied base of operations in Europe. Hitler hoped that Britain would negotiate an armistice, for which he was willing to make generous concessions. However, Hitler's tentative offers were rejected by the Churchill coalition government which - partly thanks to the successful execution of Operation Dynamo - was determined to fight on. 

Directive No. 16

During the Battle of Britain, Hitler issued a directive (Directive No. 16) to the German armed forces (Wehrmacht) ordering preliminary preparations for an invasion of Britain. Operation Sea Lion (Unternehmen Seelöwe) was the codename for this mission and the barges and landing craft were assembled in readiness.

Air superiority or air supremacy was required before this could be carried out. The Luftwaffe's mission 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 try to prevent a sea landing.

On August 1, Hitler issued a directive (Directive No. 17) to the Luftwaffe's commander-in-chief, Reichsmarschall (Empire Marshal) Hermann Göring, and the Oberkommando der Luftwaffe (High Command of the Air Force) to launch the air assault.

Target Fighter Command

The most important target was RAF Fighter Command. The destruction of the service would deprive the British of their air superiority asset. The Germans prepared for Adlertag throughout July and early August. The assault date was pushed back several times due to inclement weather. It was finally carried out on 13th August 1940.

Order of battle

The following targets were chosen for attack on 13 August 1940:

German Bomber Unit Target
Kampfgeschwader 1 (KG 1) RAF Biggin Hill in Kent.
Kampfgeschwader 76 (KG 76) RAF Kenley in Greater London and RAF Debden in Essex.
Kampfgeschwader 2 (KG 2) RAF Hornchurch in Essex, RAF Eastchurch and RAF Manston in Kent.
Kampfgeschwader 3 (KG 3) RAF Eastchurch in Kent.
Kampfgeschwader 53 (KG 53) RAF North Weald in Essex.
Erprobungsgruppe 210 Radar Stations at Rye (East Sussex), Pevensey (East Sussex) and Dover (Kent). RAF Hawkinge & RAF Manston in Kent, RAF Kenley in Greater London.
Kampfgeschwader 4 (KG 4) Land targets unknown due to records being lost, mine laying operations at sea.
Kampfgeschwader 40 (KG 40) RAF Dishforth in Yorkshire.
Kampfgeschwader 26 (KG 26) RAF Dishforth & RAF Linton-on-Ouse in Yorkshire.
Kampfgeschwader 30 (KG 30) RAF Driffield in Yorkshire.
Kampfgeschwader 27 (KG 27) Ports of Bristol, Birkenhead and Liverpool.
Lehrgeschwader 1 (LG 1) RAF Worthy Down in Hampshire, RAF Detling in Kent, Ports of Southampton, Portsmouth and surrounding airfields.
Sturzkampfgeschwader 3 (StG 3) For unknown reasons it was removed from the order of battle on 13 August, possibly due to missions being cancelled owing to poor weather.
Kampfgeschwader 51 (KG 51) RAF Bibury in Gloucestershire, Spithead harbour in Hampshire, Ventnor radar station on the Isle of Wight.
Kampfgeschwader 54 (KG 54) RAF Croydon in London, RAF Farnborough & RAF Odiham in Hampshire, the Fleet Air Arm base in Gosport, Hampshire.
Kampfgeschwader 55 (KG 55) RAF Middle Wallop in Hampshire, targets in Plymouth, Devon and Feltham, Hampshire.
Sturzkampfgeschwader 1 (StG 1) RAF Warmwell in Dorset, RAF Detling in Kent.
I., and II./Sturzkampfgeschwader 2 (StG 2) RAF Middle Wallop in Hampshire, RAF Warmwell in Dorset, Portland area and airfields, Yeovil.
Sturzkampfgeschwader 77 (StG 77) RAF Warmwell in Dorset, Portland area.

The battle

Over a ten-hour period, waves of powerful attacks were launched against Essex, Kent, Sussex, and Hampshire. On 'Eagle Day,' the Luftwaffe flew 1,485 sorties (missions), with Fighter Command responding with 727 sorties.

Hundreds of Luftwaffe planes bombed radar stations and fighter airfields in southern England. They were met with fierce RAF resistance and had to contend with a sophisticated air defence system that used radar, supplemented by the Royal Observer Corps, to pinpoint the number and direction of incoming enemy aircraft and send fighters up to intercept, Hurricanes to attack the bombers, and Spitfires to take on their Me109 escorts.

Poor intelligence hampered the German attack. They never understood the significance of the radar stations, or how Britain's outnumbered fighters could be directed by ground control to attack specific flights without the need for costly defensive patrols. As information came in, the WRAF personnel manning the massive tables moved counters across the maps, allowing Dowding and Fighter Command to order planes to scramble to meet the attackers.

The Luftwaffe planes had to use fuel to get to their destinations, and they only had minutes of effective flying time left when they arrived before being forced to turn back. The RAF, on the other hand, was nearby, allowing their planes to stay in the fight for longer. Downed RAF pilots who survived could be rescued and quickly returned to service, whereas their German counterparts were captured.


Throughout the Battle of Britain, both sides overestimated enemy losses, and on Adlertag, the RAF claimed 78 Luftwaffe planes destroyed, when the actual number was 47 or 48 destroyed, and 39 severely damaged.

The Germans claimed to have shot down 70 British fighters in the air, with additional fighters and bombers destroyed on the ground, but actual British losses were less than one-third of those claims. The Luftwaffe's heavy losses did not deter them from continuing their attacks into September, until the Luftwaffe switched to night strategic bombing.


The German attacks on 13 August caused significant damage and casualties on the ground, but they had little impact on Fighter Command's ability to defend British airspace due to poor intelligence and communication.

Some German planes bombed the wrong targets and, crucially, failed to identify the factories where RAF fighters were manufactured. According to German estimates, Britain could produce approximately 250 fighters per month, whereas the actual figure was twice that.

Southampton suffered some damage, but the only airfields affected were Coastal Command stations, leaving British fighter defences unaffected. Three major Luftwaffe objectives were completely missed: Odiham, Farnborough, and Rochford.

However, the day's operations demonstrated how difficult it was for British defences to meet the Germans with forces large enough to inflict significant losses.

Göring's failure

Göring had promised Hitler that Adlertag and Adlerangriff would produce the desired results in days, if not weeks.  It was supposed to be the end of RAF Fighter Command, but Adlertag and the subsequent operations failed to destroy the RAF or gain the required local air superiority. As a result,

Operation Sea Lion was put on hold indefinitely.