In February 1941, 7./JG 26 under Hpt Joachim Müncheberg operated in the Mediterranean theatre against Malta from bases in Sicily. In addition to flying missions over Malta, 7./JG 26 also flew over Yugoslavia in support of the German invasion of the Balkans. The 7./JG 26 presence in Sicily was meant to reduce the losses of German Fliegerkorps X and Italian bombers over Malta by reducing the ability of the RAF defenders to interfere with their raids. Malta's position in the Mediterranean threatened the transport of Rommel's troops and equipment across to Tunisia. This was only weeks after the Axis raids on Malta had failed to sink the damaged carrier HMS Illustrious as she lay helpless in the Valletta docks. The 7./JG 26's short campaign over Malta is often heralded as "exceptional" by writers such as Donald Caldwell, with the Staffel claiming a large number of the Hawker Hurricanes of No. 261 Squadron RAF shot down. This was because Müncheberg chose the most liberal implementation of the Freijagd role, avoiding combat with the Hurricanes unless he had the advantages of height and numbers, and often picking off stragglers. Whilst this helped Müncheberg with his personal quest to gain the Oak Leaves to his Knight's Cross, he being a pronounced suffer of the condition jokingly referred to by Luftwaffe pilots as "throat-ache" (the strong desire to win the throat decoration of the Knight's Cross of the Iron Cross and the three possible upgrades to it: the Oak Leaves, the Swords, and the Diamonds), it meant 7./JG 26 did not protect the German and Italian bombers and recce aircraft over Malta as they could have. No. 261 Squadron actually claimed more Axis aircraft shot down during the period than the 7./JG 26 did. German losses were particularly high on the days they mounted mass air raids, such as the Junkers Ju 87 attacks on 23 March 1941 when the Hurricanes claimed nine Stukas for only one Hurricane lost, despite the Bf 109 escorts. Whilst the constant threat of the fast and high-flying 109s had a pronounced effect on the morale of the No. 261 Squadron pilots, the losses the Hurricanes inflicted on the Axis bombers (along with Malta's strong anti-aircraft defences) meant the majority of German raiders switched to inaccurate night attacks, which was the opposite of what the Luftwaffe had hoped 7./JG 26 would achieve. In spite of this, Müncheberg got his Oak Leaves on 7 May 1941.
The air operations in conjunction with the Dieppe Raid resulted in some of the fiercest and most intensive air battles since 1940. The RAF’s objectives were to throw a protective umbrella over the naval and ground forces involved and to force the Luftwaffe fighters into an attritional conflict on the Allies’ own terms.
The Allies committed fifty-one fighter squadrons of Spitfires and Typhoons, 8 squadrons of Hurricane fighter-bombers, 4 squadrons of reconnaissance Mustang Mk Is, and 7 squadrons of light bombers.
Opposing were the 115 operational fighters of the two Jagdgeschwader units that were charged with protecting the Western Front: JG 2 and JG 26. All of the other Jagdgeschwader units were charged with protecting the Eastern Front, North Africa, and a few other areas. JG 2 and JG 26, in addition to flying the Bf 109s, were also flying the new Fw 190s. However, all totalled, the German fighters were outnumbered by three to one.
Although initially slow to respond to the raid, the German fighters soon made their presence felt over the port as the day wore on. While the Allied fighters were moderately successful in protecting the ground and sea forces from aerial bombing, in the air the RAF fighters were second best versus the experienced and well-equipped Jagdgeschwader.
While RAF Fighter Command claimed to have inflicted heavy casualties on the Luftwaffe, the balance sheet showed the reverse; Allied aircraft losses amounted to 106, including 88 RAF fighters (of which 70 Spitfires were lost to all causes) and 18 bombers, against 48 Luftwaffe aircraft lost. Included in that total were 28 bombers, half of them Dornier Do 217s from KG 2. The two German Jagdgeschwader units had the following results: JG 2 lost 14 Fw 190s with eight pilots killed and JG 26 lost six Fw 190s with six pilots killed. The Spitfire Squadrons (42 with Mark Vs, and four with Mark IXs) were tasked with ground attack, escort and air-superiority missions, so the exact number of Spitfire losses to the Fw 190 is unknown. The Luftwaffe claimed 61 of the 106 RAF machines lost, which included all types: JG 2 claimed 40 kills and JG 26 claimed 21 kills.
At the end of March 1942, a specialist fighter-bomber Staffel was created; 10.(Jabo)/JG 26. Equipped with the Fw 190 A-3/U3, along with sister unit 10.(Jabo)/JG 2, the Staffel operated from June onwards against channel shipping and port towns on the south-eastern coasts of England. Often operating in small numbers at high speed and low altitude, these pin-prick raids were almost impossible for the RAF fighters to defend against. On 31 October 1942, Canterbury was attacked in the largest daylight raid mounted by the Luftwaffe since the Battle of Britain, with some 60 Fw 190s attacking the city, killing 32 and injuring 116 (one Fw 190 was lost). The most effective counter to these attacks were wasteful standing patrols by the Hawker Typhoon and the Griffon engined Spitfire Mk XII, which were both fast enough at low level to catch the Fw 190. As 1943 progressed, however, the Jabo units were suffering ever higher losses. For example, in the London raid of 20 January 1943, JG 26 Jabos and their escorts (some 90 fighters in all) lost eight aircraft and pilots to the RAF.
In February 1943, 10.(Jabo)/JG 26 became 10.(Jabo)/JG 54, but continued to operate under the control of JG 26. In April these Jabo units were amalgamated into IV Gruppe, Schnellkampfgeschwader 10 (SKG 10) and switched to night operations over southern England.
In 1943, the unit was increasingly involved in operations against a new enemy, in the form of the increasingly intensive daylight heavy bomber operations of the USAAF Eighth Air Force. The bomber formations were initially the bait with which to lure the Luftwaffe fighters into combat, although the bombers also now had the capability to destroy or severely damage their ground targets. The Luftwaffe's Fw 190's performance fell off rapidly above 25,000 feet, and thus massed head-on attacks were developed to maximise the fighter's firepower and to exploit both the B-17E and F model Flying Fortresses', and B-24D Liberators' weaknesses in forward-facing armament, a deficiency partly corrected in late-model production versions of both heavy bombers.
Meanwhile, JG 26 were notified that they were to be posted to the Eastern Front, replacing JG 54 who were to transfer West. The changeover was to be by Gruppe strength, and I./JG 26 (under Major Johannes Seifert) and 7./JG 26 (Hpt. Klaus Mietusch) moved into Northern Russia in late January 1943. However, during the spring of 1943 the planned phased transfer was postponed, and by early June I./JG 26 was back in France, as was 7./JG 26 in July. Some 199 Soviet Air Force aircraft had been claimed shot down, for just 11 pilots killed.
Jagdgeschwader 26's first operations during the Normandy invasion on 6 June 1944 was conducted by Group Commander Josef Priller, flying an Fw 190A-8, and his wingman from his airfield at Lille-Nord; an event that would be portrayed graphically in the book by Cornelius Ryan and the resultant film The Longest Day. Priller and his wingman took off in their Focke-Wulfs and headed west at low altitude, dodging several formations of Spitfires in the process. Crossing the coast at Le Havre the duo spotted the ships of the assault force. The pair made a high-speed strafing pass over what was the British Sword Beach. Anti-aircraft fire forced the unscathed Focke-Wulfs to seek cloud cover. JG 26 (with JG 2) flew the bulk of the 172 sorties by the Luftwaffe Fighter arm on D-Day. By contrast the Allies Air Forces flew 14,000 sorties the same day.
The Luftwaffe's fighters were mobilised as part of a long-standing plan in the event of an invasion to reinforce the French-based units of JG 2 and JG 26 with home-located Reich Defence Gruppen. Alongside these some 20 Gruppen from the newly arrived Jagdgeschwaders under the command of Jagd Division 5, JG 26 would fly intensively over the invasion battlefield during the summer of 1944, flying sweeps against the ever-present hordes of Allied fighter-bombers. Inevitably the overwhelming Allied air superiority inflicted heavy losses on pilots and planes. By late summer, few of the battle-hardened JG 26 Experten of earlier years remained with the Geschwader, with novice recruits of less than 180 hours' flying experience drafted in. JG 26 claimed just 30 kills in July, and suffered 20 pilots killed and 16 injured.
By late August, the Geschwader was stationed in Belgium, mustering just 56 aircraft. JG 26 claimed 76 kills for the month, with 40 pilots killed in action (their highest monthly loss of the war), 6 killed in accidents, and 20 injured. The Geschwader, located close to the Dutch border, was heavily involved in operations against Operation Market Garden, the airborne offensive around the Rhine bridges. Efforts to disrupt the transport aircraft were thwarted by the numerous Allied fighter patrols. Major Klaus Mietusch, the 72-kill ace commander of III./JG 26, and the longest-serving member of the Geschwader (since 1938), was killed in combat at this time. In November 1944, II Gruppe withdrew to re-equip with the improved Fw 190 D-9 the 'Dora'.
On 1 January 1945, JG 26 took part in Operation Bodenplatte, the low-level massed fighter attacks on the Allied air bases in the Low Countries. Led by Oberst Priller, over 60 Fw 190D's of I./JG 26 and the subordinated III./JG 54 attacked the RAF airfield at Grimbergen, destroying 5 bombers and a Mustang, along with various trucks and equipment. However, 24 aircraft failed to return, over half falling to German friendly fire. II./ JG 26 and III./JG 26 meantime attacked Brussels-Evere the home of the RCAF's crack No 127 Wing, flying Spitfires. Just 11 Spitfires were destroyed, the attackers losing 17 aircraft. JG 26's losses were indicative of the Luftwaffe's casualties that day, with some 300 of the 900 fighters involved failing to return safely. The operation marked the end of the Luftwaffe's hopes for effective and concerted operations against the Allies in the future. During the course of the war, the unit lost 830 pilots: 763 pilots were killed (631 in action and 132 in accidents) and 67 were shot down and became prisoners-of-war.