The unit engaged in both strategic bombing, close air support, anti-shipping and aerial interdiction operations.

The majority of its operational life – not entirely unlike another Luftwaffe wing designated KG 40 — was spent on anti-shipping missions.

On 7 September the units assaulted rail targets in the Lvov area in support of the German Fourteenth Army.

[6] On 28 October 1939, a Heinkel He 111H bomber from KG 26, bearing the Geschwaderkennung of 1H+JA (the "A" denoting the Geschwaderstab or command flight), officially became the first German aircraft to be shot down on British soil by the Royal Air Force.

As it returned from a reconnaissance over the Firth of Clyde, Supermarine Spitfire fighters of 602 and 603 Squadron intercepted the bomber over Inchkeith.

It crash landed near the small hamlet of Humbie, near the town of Dalkeith in East Lothian, Scotland,[4][7] and is often referred to as the 'Humbie Heinkel'.

[8] On 22 February 1940, a Heinkel He 111 bomber from KG 26 bombed and sank the Z1 Leberecht Maass, who lost 280 of her crew and was survived by 60.

[9][11] During operations to save the crew, the Z3 Max Schultz also sank when it hit a mine, losing all hands.

[12] Hitler ordered a court of inquiry to be convened to investigate the cause of the losses and it concluded that both ships that been sunk by bombs from the He 111.

On 16 March 1940 3.Staffel attacked Scapa Flow and hit HMS Norfolk and one other ship, though the latter was not significantly damaged.

[4] I./KG 26 was based at Marx, near Wilhelmshaven and made cross-water attacks against Norwegian Navy coastal batteries at Kristiansand and near Oslofjord.

On 10 April the unit made an attack on Scapa Flow to disrupt potential British Naval reinforcements to Scandinavia.

During the campaign in Norway the Gruppe made several attacks on Allied Destroyers, Cruisers and transports without success.

The unit undertook tactical strikes against Norwegian Army positions in the south of the country until 1 May 1940.

On 9 June it sank two transports and attacked HMS Ark Royal, west of Bodø.

[3] Incomplete loss records show that KG 26 lost at least 40 aircraft (70% or greater damage) from April 9 to June 9, 1940.

It suffered heavy losses on 15 August 1940, when the Gruppe was intercepted out to sea when attempting to raid Dishforth losing seven aircraft.

On 27 April it sank the catapult ship HMS Patia off the mouth of the River Tyne.

During the Balkans Campaign the unit moved to Foggia in northern Italy and conducted raids against Yugoslavia as part of VIII.

Staffel, II.Gruppe, KG 26 (6.II./KG 26) was rebased at Saki, in the Crimea and began operations over the Black Sea against the Soviet Navy.

In June 1942 the units was once again renamed, and its fourth formation was to continue until the disbanding of Kampfgeschwader 26 at the end of the war.

The Gruppe was ordered to Grosseto to counter Operation Torch, the American landings in Morocco and Algeria on 8 November 1942.

[14] On 22 December 1942, Ju 88s from III Gruppe', KG 26 torpedoed and damaged the British troopship Cameronia.

On 12 August the unit struck at Allied shipping in the western Mediterranean losing 10 machines for little result.

In late August early September the unit moved to southern France at Salon-en-Provence.

I./KG 26 did convert onto the Ju 88, but owing to fuel shortages the unit was merged into I. and III./Kampfgeschwader 77 in early June.

These units were constantly moved, participating in attacks against the Allied landings in Southern France under Operation Anvil.

Its most notable action was attacking Convoy PQ 18 in September 1942, whilst operating from Banak, Norway.

On 23 February 1945 it flew its last combat mission sinking the Liberty ship SS Henry Bacon.

[20] In May 1945 it began to rescue encircled German soldiers from the Courland pocket as the Red Army closed in.