'DW' was a British naval undertaking to destroy the German naval forces which had reached and taken Narvik in the 'Naumburg' sub-operation of 'Weserübung' (10/13 April 1940).

Commanded by Kapitän Friedrich Bonte, this Gruppe I comprised the destroyers Georg Thiele of Fregattenkapitän Fritz Berger’s 1^st Zerstörer-Flottille, Wolfgang Zenker, Bernd von Arnim, Erich Giese and Erich Koellner of Fregattenkapitän Erich Bey’s 2^nd Zerstörer-Flottille, and Diether von Roeder, Hans Lüdemann, Hermann Künne, Wilhelm Heidkamp and Anton Schmitt of Fregattenkapitän Hans-Joachim Gadow’s 3^rd Zerstörer-Flottille.

The day after the German invasion, the Royal Navy took an opportunity to intervene, and Captain B. A. Warburton-Lee’s 2^nd Destroyer Flotilla, comprising Hardy, Hotspur, Havock, Hunter and Hostile, each of them smaller and more lightly armed than the German destroyers they were to fight, steamed up the Ofotsfjord in the early morning.

The German picket ship, Diether von Roeder, had left her post as a result of a misunderstanding and, as it approached Narvik in the opening stages of the 1^st Battle of Narvik, the British flotilla therefor surprised and engaged a German force at the entrance to the harbour in a blinding snowstorm and sank Wilhelm Heidkamp (in which Bonte was killed) and Anton Schmidt, heavily damaged Diether von Roeder and inflicted lesser damage on two other German destroyers. The British ships also exchanged fire with the German invasion troops ashore, but did not have a landing force aboard and therefore turned to leave.

The British destroyers were then engaged by three more German destroyers (Wolfgang Zenker, Erich Koellner and Erich Giese) emerging from the Herjangsfjord under Bey’s command, and then two more (Georg Thiele and Bernd von Arnim) coming from Ballangen Bay under Berger’s command. In the ensuing battle, two British destroyers were lost: the flotilla leader Hardy, which was beached in flames with the mortally wounded Warburton-Lee still on board, and Hunter, which was torpedoed and sank; Hotspur was also damaged badly by a torpedo.

Hotspur and the other remaining British destroyers left the scene of the engagement, damaging Georg Thiele as they did so. The German destroyers, now short of fuel and ammunition, did not pursue, and the British ships were able to sink seven German or German-seized transport ships outside Narvik port, including the 8,460-ton ammunition supply ship Rauenfels.

Soon the German naval forces were blocked in by British reinforcements, including the light cruiser Penelope.

On 11 April Erich Koellner sustained further damage when the vessel ran onto uncharted rocks. As the British destroyers left the Vestfjord outside Narvik, the submarines U-25 and U-51 fired torpedoes at them, but German torpedoes at the time had severe problems with their magnetic detonator systems, and all of the weapons either did not detonate at all or detonated well before their targets.

Both the German and British commanders (Bonte in Wilhelm Heidkamp and Warburton-Lee in Hardy) had been killed in the battle, and the overall figure for German casualties was 163.

The Royal Navy considered it imperative, for morale and strategic purposes, to defeat the German force in Narvik, so Vice Admiral W. Whitworth, commander of the Home Fleet’s Battle-Cruiser Squadron, was despatched with the battleship Warspite and nine destroyers in the form of four 'Tribal' class units (Bedouin, Cossack, Punjabi and Eskimo) and five others (Kimberley, Hero, Icarus, Forester and Foxhound), accompanied by aircraft from the fleet carrier Furious. This force arrived in the Ofotfjord on 13 April to find that the eight remaining German destroyers, now under the command of Bey, were virtually stranded for lack of fuel and were short of ammunition.

During the opening stages of the 2^nd Battle of Narvik, a Fairey Swordfish single-engined biplane launched from Warspite bombed and sank Korvettenkapitän Georg-Wilhelm Schulz’s U-64, at anchor in a side-fjord near Bjerkvik. Most of the crew survived and were rescued by German mountain troops. This was the first U-boat to be sunk from the air in World War II.

In the ensuing battle, three of the German destroyers were sunk by Warspite and her escorts, and the remaining five were scuttled by their own crews when they ran out of fuel and ammunition.

First was Erich Koellner, which was trying to ambush the Allied force but was spotted by the Warspite's Swordfish and subsequently torpedoed and shelled by the destroyers and battleship.

Then Wolfgang Zenker, Bernd von Arnim, Hans Lüdemann and Hermann Künne engaged the British force, but managed to inflict only light damage on Bedouin.

British aircraft from Furious tried to engage the German destroyers but were unsuccessful, and two of their number were lost. Wolfgang Zenker sought unsuccessfully to torpedo Warspite. Finally, when they had expended almost all their ammunition, all but one of the German destroyers retreated. That which did not was Hermann Künne, which did not receive the order: this destroyer was taken under fire by the pursuing Eskimo, but sustained no hits.

Out of ammunition but undamaged, Hermann Künne was scuttled by her crew in Trollvika in the Herjangsfjord: the crew placed demolition depth charges on the ship, attempting to sink her in Trollvika’s shallow waters. Eskimo now fired a torpedo which hit the sinking Hermann Künne, setting her on fire. Whether the Germans' own depth charges or Eskimo's torpedo was the source of explosion remains moot, and Eskimo was in turn ambushed by Georg Thiele and Hans Lüdemann, the British destroyer losing her bow but surviving.

Both suffering engine problems, Diether von Roeder and Erich Giese fired on the British force while still lying alongside, and damaged Punjabi and Cossack before being sunk by British fire. That was the last German counterattack, and the remaining German destroyers were scuttled soon after this.

The only German vessel to survive within the port area was U-51.

Shore batteries and installations were also very badly damaged by Warspite's 15-in (381-mm) guns.

On the Allied side, damage repairs kept Eskimo in Norway until 31 May.

German submarines again suffered torpedo failures as U-46 and U-48 fired at the departing Warspite on 14 April.

The British suffered damage to three destroyers as well as 28 men killed and 55 wounded, while the Germans lost 128 men killed and 67 wounded, as well as the destroyers Hermann Künne, Wolfgang Zenker, Erich Koellner, Georg Thiele, Bernd von Arnim, Erich Giese, Hans Lüdemann and Diether von Roeder, in addition to U-64. About 2,600 of the surviving naval personnel were organised into an improvised marine infantry unit, the so-called Gebirgsmarine, which fought alongside the 139^th Gebirgsjägerregiment in the subsequent land battle.