Heavy raid on Portsmouth. Convoy in Thames Estuary, radar stations and coastal airfields attacked.

Night: Widespread harassing raids.

Weather: Fine with some mist patches.

Enemy Action by Day

On the eve of Adler Tag (Eagle Day), the Luftwaffe launched a powerful and highly coordinated assault across southern England in what amounted to a full-dress rehearsal for the long-anticipated aerial offensive. Though Göring had designated 13 August as the formal start of the assault on Britain’s air defences, operations on the 12th marked a dramatic escalation. Radar installations, Channel convoys, and airfields were all targeted in a sequence of concentrated strikes designed to blind and destabilise Fighter Command’s front-line response.

07:20–09:00 Hours: Attacks on the Radar Chain

At 07:20 hours, radar stations along Britain’s south-east coast picked up a fast, low-flying formation emerging from the Calais region. It was Erprobungsgruppe 210—an elite Luftwaffe unit of Bf 110 fighter-bombers under the command of Hauptmann Walter Rubensdörffer—executing a coordinated strike on the British Chain Home radar network. The mission aimed to blind Fighter Command’s early warning system ahead of the Luftwaffe’s main assault.

Rubensdörffer divided his force into four sections, each targeting a key radar station. Oblt. Wilhelm Rössiger’s section attacked the installation at Rye, damaging the accommodation block and rendering the radar temporarily inoperative. At Pevensey, Oblt. Martin Lutz’s flight inflicted greater disruption: a 500 kg bomb severed the primary power cable, knocking out the station and leaving it without power for several hours. Oblt. Otto Hinze’s detachment bombed the Dover site, damaging several outbuildings and electrical components, though the main transmission towers remained functional. Rubensdörffer himself led the attack on the Dunkirk (Canterbury) radar station, but morning haze and navigational imprecision caused only minor damage.

The raids succeeded in disabling three radar stations for several hours, significantly hampering Fighter Command’s coverage along the south-east coast. Although Ventnor on the Isle of Wight remained unaffected during this phase, the temporary disruption of coastal radar left a critical gap in the RAF’s early warning screen. Crucially, the Luftwaffe misjudged the outcome—believing the radar sites had been destroyed and that Britain’s defensive network was permanently compromised.

11:00 Hours: Dive-Bombing of Convoys Arena and Agent

Shortly before midday, IV./Lehrgeschwader 1 launched a concentrated dive-bombing assault against two British convoys moving through the Thames Estuary—codenamed Arena and Agent. Led by Hauptmann Erwin Röder, the Ju 87 Stukas swept in low from altitude, their Jericho-Trompete sirens wailing as they plunged towards their targets. Providing top cover were Bf 109s of III./Jagdgeschwader 26.

The RAF mounted a rapid response. Hurricanes from Nos. 151 and 501 Squadrons, together with Spitfires from No. 65 Squadron, intercepted the raiders as they descended through the coastal cloud base. The dogfights that followed over the estuary were chaotic and intense, with aircraft weaving through anti-aircraft bursts and smoke rising from damaged ships below. In the confusion, the RAF lost four fighters, with two pilots killed. One Ju 87 was confirmed shot down, but the German formation succeeded in completing its bombing run.

The Stukas inflicted heavy damage. Several vessels were hit amidships or near their superstructures, causing fires and structural collapse. Eyewitnesses along the coast later described scenes of devastation—burning hulls drifting in the estuary, lifeboats scattered across the water, and thick columns of smoke rising from the Channel.

11:51–12:45 Hours: Strike on Ventnor and the Portsmouth Raid

At 11:51 hours, radar stations along the south coast detected a massive Luftwaffe raid assembling over Cherbourg. The formation comprised 63 Junkers Ju 88 bombers from KG 51 and KG 54, escorted by over 120 Messerschmitt Bf 110s of ZG 2 and ZG 76, with additional high cover provided by Bf 109s of Jagdgeschwader 53. It was one of the largest coordinated attacks of the campaign to date.

As the bombers crossed the southern coastline, a splinter formation of fifteen Ju 88s from KG 51 broke away. This group, led by the unit’s Kommodore, Oberst Dr Johannes Fisser, was tasked with neutralising the Chain Home radar installation at Ventnor on the Isle of Wight. In a precisely executed strike, Fisser’s aircraft released four 250 kg bombs directly onto the radar site. The explosions tore through the operations buildings and reduced the transmission towers to mangled wreckage. The station was completely disabled and would remain offline for nearly two weeks—blinding a critical sector of Britain’s early warning network during a pivotal phase of the air campaign.

The raiders were met by Spitfires from No. 152 Squadron and Hurricanes from No. 145 Squadron. Fisser’s Ju 88, having completed its run, was hit—likely by a combination of ground fire and RAF interception—and crash-landed near Godshill Park. Oberst Fisser was killed, but two of his crew survived and were captured. His death was a significant blow to KG 51, which would later name a Staffel in his honour.

Meanwhile, the main force continued eastward and unleashed the Luftwaffe’s first major bombing assault on a British city. Portsmouth—home to the Royal Navy’s largest dockyard—bore the brunt of the attack. Despite fierce resistance from naval and army anti-aircraft batteries, dozens of high-explosive and incendiary bombs struck the naval base, industrial works, and surrounding residential districts. Fires raged throughout the city, and over 100 civilians were killed, making it the deadliest single air raid on British soil to date.

RAF Fighter Command scrambled over 60 fighters from airfields at Tangmere, Middle Wallop, Warmwell, and Exeter, but many arrived after the bombing was underway. Nevertheless, the counterattack claimed a heavy toll on the raiders. Eleven Ju 88s, five Bf 110s, and two Bf 109s were destroyed in a series of running engagements across southern Hampshire and the Channel. Among the RAF pilots, Pilot Officer W.S. Williams of No. 152 Squadron (RNZAF) distinguished himself by shooting down a Ju 88 before being forced to land near Bembridge. He escaped moments before his Spitfire exploded in flames.

12:50–17:30 Hours: Luftwaffe Strikes on RAF Airfields

The next phase of the Luftwaffe’s offensive shifted to RAF airfields across south-east England, as German commanders sought to destroy Fighter Command’s forward operating bases.

At 12:50 hours, Erprobungsgruppe 210—flying Bf 110s and bomb-laden Bf 109s—launched a precision assault on RAF Manston. No. 65 Squadron was in the midst of scrambling when the first bombs struck. Most aircraft managed to take off, but Pilot Officer Kenneth Hart’s Spitfire was damaged during his take-off run, forcing him to abandon the sortie.

The raid on Manston was brief but devastating. In the space of five minutes, over 150 high-explosive bombs tore through the airfield, gouging more than 100 craters into the chalk subsoil and blasting apart two hangars. The station workshops were obliterated in a direct hit, killing a civilian clerk. The scale of the bombardment sent immense plumes of white chalk dust billowing skywards—so thick that aerial observers mistakenly believed the airfield was engulfed in flames. Moments later, a follow-up wave arrived: Dornier Do 17s of I./KG 2, escorted by Bf 109s from JG 54, swept over the battered field to intensify the destruction.

No. 56 Squadron, flying Hurricanes, was vectored to intercept the incoming force. Among the defenders was Pilot Officer Geoffrey Page, flying Hurricane P2970. As his section closed in on the bombers, Page’s aircraft was hit by return fire—his fuel tank ignited, and flames engulfed the cockpit. Though severely burned, he unfastened his harness, forced open the canopy, and bailed out, parachuting into the Channel. He was later rescued by a passing merchant vessel. Page’s injuries were grievous—his face and hands extensively burned—but he would survive, endure months of reconstructive surgery, and ultimately return to combat, becoming one of Fighter Command’s most determined and inspiring figures. Despite the damage inflicted at Manston, ground crews worked through the night, and the airfield was operational again within 24 hours.

Later in the afternoon, at 17:30 hours, RAF Hawkinge became the next target. Once again, Erprobungsgruppe 210 struck with Bf 110s, delivering a concentrated ten-minute attack that left the station reeling. A direct hit destroyed No. 3 hangar; No. 5 hangar sustained serious damage; fires broke out in the main stores building and clothing depot. Two married quarters were flattened. Bomb damage assessment identified 28 craters across the site, some plunging as deep as 28 ft. Seven men were killed—including three RAF airmen and two civilian contractors—and six others were seriously injured. The raid caught the ground defences largely by surprise, with only two Hispano cannons managing to return fire. Nevertheless, Hawkinge remained partially operational and emergency repairs began before nightfall.

Shortly thereafter, RAF Lympne was bombed by Ju 88s of II./KG 76, escorted by Bf 109s of I./JG 26 led by Hauptmann Kurt Fischer. High-explosive bombs rained across the airfield, hitting dispersal pens, the landing ground, and hangars, setting off fires and causing extensive damage. Two aircraft were destroyed on the ground, and several more were rendered unserviceable. Though less heavily hit than Manston or Hawkinge, the attack significantly reduced Lympne’s operational capacity.

Spitfires from No. 610 Squadron were scrambled to intercept the German formation and engaged the escorting Bf 109s. In the ensuing dogfight, two RAF fighters were lost. Among the German casualties was Oberleutnant Friedrich Butterweck of JG 26, who was killed when his Bf 109 exploded mid-air over Ashford.

Fighter Sweeps and Evening Losses

One of the day’s most significant Luftwaffe losses occurred at approximately 12:35 hours, when Hauptmann Harro Harder, Gruppenkommandeur of III./JG 53, was shot down during a fighter sweep over the Isle of Wight. Likely brought down by Spitfires of No. 609 Squadron, Harder’s aircraft crashed into the Channel, and his body was later recovered near Dieppe. A respected ace and aggressive leader, Harder had claimed five Spitfires in just 48 hours the previous week.

Elsewhere, II./JG 52—newly transferred to the Channel front—suffered its first combat losses. Three Bf 109s were shot down, including one piloted by Unteroffizier Leo Zaunbrecher, who was engaged by Pilot Officer J. McLintock of No. 615 Squadron and captured after crash-landing in Sussex.

Later in the afternoon, III./JG 26 launched a free-hunting (Freie Jagd) patrol over the Dover area, seeking to draw out RAF fighters. While few responded, three Spitfires were claimed by Luftwaffe pilots—Leutnant Heinz Ebeling, Feldwebel Gerhard Gryzmalla, and Leutnant Johannes Naumann—in combat near Manston.

Reconnaissance Operations

Reconnaissance missions ranged deep across Britain throughout the day. One enemy aircraft was tracked flying inland from Shoreham as far as Northolt, while another conducted a wide sweep over South Wales and Somerset. Most notably, a Ju 88—likely from Fernaufklärungsgruppe 123—ventured more than 250 miles into the Atlantic before turning south along the Irish coastline, underscoring the Luftwaffe’s growing operational reach and the expanding scope of its strategic reconnaissance efforts.

Enemy Action by Night

After nightfall, the Luftwaffe resumed operations under cover of darkness. RAF Sealand in Cheshire was bombed by II./KG 27, marking the beginning of an increasingly coordinated night offensive against British airfields. Meanwhile, a Heinkel He 111 from 9./KG 55 returning from a raid on Bristol crashed near Rambervillers, France, resulting in the deaths of two crew members.

Elsewhere, sporadic bombing raids took place near Nottingham, Norwich, Blackpool, and Bircham Newton, though little damage was reported. Minelaying operations also continued in earnest, with activity noted off the Thames Estuary, the Bristol Channel, and along sections of the East Coast.

Summary

Monday, 12 August 1940 marked a pivotal escalation in the Luftwaffe’s campaign against Britain. In a tightly coordinated assault, German air fleets struck with unprecedented intensity—targeting Chain Home radar stations, coastal convoys, RAF airfields, and civilian infrastructure. The radar site at Ventnor was knocked out; airfields at Manston, Hawkinge, and Lympne were badly damaged; and Portsmouth endured its most devastating air raid to date, with dockyards and homes set ablaze.

Convinced these blows had crippled Britain’s defensive system, the Luftwaffe believed Fighter Command was nearing collapse.

They were mistaken.

Repair crews worked swiftly. By nightfall, all but one radar station were back online. Damaged airfields remained operational. Though Fighter Command lost 18 aircraft and 11 airmen, its core strength held. The system bent under pressure—but it did not break.

German Losses:
Airmen: 52 | Aircraft: 32

British Losses:
Airmen: 11 | Aircraft: 18

Hurricane P3304, No. 151 Squadron. Aircraft destroyed.
P/O R.W.G. Beley. Died of wounds. Shot down by Bf 109. Crashed into sea and rescued. Taken to Manston.
http://www.bbm.org.uk/airmen/Beley.htm

Spitfire K9999, No. 152 Squadron. Aircraft lost.
P/O D.C. Shepley. Missing in action. Last seen in combat with Ju 88. Failed to return to base.
http://www.bbm.org.uk/airmen/Shepley.htm

Spitfire P9456, No. 152 Squadron. Aircraft destroyed.
F/L L.C. Withall. Missing in action. Shot down by gunfire from Ju 88, believed crashed into sea.
http://www.bbm.org.uk/airmen/Withall.htm

Hurricane R4180, No. 145 Squadron. Aircraft destroyed.
P/O J.H. Harrison. Missing in action. Shot down over Channel during combat with Ju 88s and Bf 110s.
http://www.bbm.org.uk/airmen/HarrisonJH.htm

Hurricane P3391, No. 145 Squadron. Aircraft lost.
Sgt J Kwiecinski. Missing in action. Failed to return to base.
http://www.bbm.org.uk/airmen/Kwiecinski.htm

Hurricane R4176, No. 145 Squadron. Aircraft destroyed.
F/L W. Pankratz. Missing in action. Shot down over Channel during combat with enemy aircraft.
http://www.bbm.org.uk/airmen/Pankratz.htm

Spitfire P9333, No. 266 Squadron. Aircraft destroyed.
P/O D.G. Ashton killed. Aircraft burst into flames from gunfire from enemy aircraft.
http://www.bbm.org.uk/airmen/AshtonDG.htm

Hurricane P2802, No. 213 Squadron. Aircraft destroyed.
Sgt S.G. Stuckey. Missing in action. Shot down over Channel by Bf 109s.
http://www.bbm.org.uk/airmen/Stuckey.htm

Hurricane P2854, No. 213 Squadron. Aircraft lost.
Sgt G.N. Wilkes. Missing in action. Last seen in combat with Bf 109s. Failed to return to base.
http://www.bbm.org.uk/airmen/Wilkes.htm

Hurricane P3662, No. 257 Squadron. Aircraft lost.
P/O J.A.G. Chomley. Missing after a combat with enemy aircraft off Portsmouth.
https://www.bbm.org.uk/airmen/Chomley.htm

Hurricane P3803, No. 501 Squadron. Aircraft lost.
F/O K. Lukaszewicz. Missing in action following combat with enemy fighters west of Ramsgate.
https://www.bbm.org.uk/airmen/Lukaszewicz.htm

Photo Descriptions

1. A view of Portsmouth Harbour (looking to the Portsmouth side) during an air raid of 12th August 1940. © IWM (MH 156)
2. Another view of Portsmouth Harbour (looking to the Portsmouth side) during an air raid of 12th August 1940. © IWM (MH 155)
3. Ventnor RDF station on the Isle of Wight under attack by Ju 88 bombers of Kampfgeschwader 51, 12 August 1940.
4. Bomb-damaged houses on the corner of Spring Garden Lane and Grove Avenue in Gosport, Hampshire, after a raid on 12 August 1940. The vicarage on the corner itself was completely destroyed. © IWM (MH 149)
5. Messerschmitt Bf 109E of 2./JG 52 resting in a wheat field after being shot down during a combat over Hastings, 12 August 1940. Its pilot, Unteroffizier Leo Zaunbrecher, was captured. © IWM (HU 104719)
6. Army officers inspect the wreckage of Messerschmitt Bf 109E-1 (W.Nr. 3367) “Red 14” of 2./JG 52, which crash-landed in a wheatfield at Mays Farm, Selmeston, near Lewes in Sussex, 12 August 1940. © IWM (HU 73928)
7. Locals watch as troops and police inspect Messerschmitt Bf 109E-1 (W.Nr. 3367) “Red 14” of 2./JG 52, which crash-landed in a wheatfield at Mays Farm, Selmeston, near Lewes in Sussex, 12 August 1940. © IWM (HU 50153)
8. No. 3 hangar at RAF Hawkinge following the attack by Erprobungsgruppe 210 on 12 August 1940.
9. Hawker Hurricane Mark Is of No 32 Squadron coming in to land for refuelling and rearming at Biggin Hill, watched by an airman standing with a signalling flag in the foreground, August 1940. © IWM (HU 54519)