Both sides in the war had an interest in securing this iron supply for themselves and denying it to the enemy, thereby setting the stage for one of the biggest battles since the Invasion of Poland.

[1] Prior to the German invasion, British forces had considered Narvik as a possible landing point for an expedition to help Finland in the Winter War.

[4] In the early morning of 9 April, the destroyers of Group I passed the Vestfjorden and arrived at the Ofotfjorden leading to Narvik, in fog and heavy snow.

Before capture Kelt managed to send a message to the coastal defence ship HNoMS Norge, alerting the local Norwegian naval commander of the incoming vessels.

[6] The German ships Wolfgang Zenker, Erich Koellner and Hermann Künne landed their soldiers in Herjangsfjord (a northern branch of Ofotfjorden) in order to capture a Norwegian regimental supply base at Elvegårdsmoen.

"[8] While this was going on, the German destroyer Wilhelm Heidkamp had positioned herself 700 m (770 yd) off the port side of Eidsvold and trained her torpedo launchers on the Norwegian ship.

Due to the difficult weather conditions, the guns' optical sights were ineffective: the first salvo fell short of the target and the next ones overshot it.

[14] Described by Kriegsmarine Admiral Erich Raeder as "an officer with reportedly pro-German feelings", he quickly withdrew from the area following the naval engagement and began negotiations with the Germans.

[29][30] According to the German plan the destroyers were supposed to have been refuelled by two tankers, Kattegat and Jan Wellem, each receiving some 600 short tons (540 t) of fuel oil.

On the 9 April morning, the British battlecruiser HMS Renown exchanged artillery salvos with the German battleships Scharnhorst and Gneisenau, which were screening the destroyers.

[7][17] The German picket ship (Diether von Roeder) had left its post to refuel, and as the British flotilla approached Narvik, they surprised and engaged a German force at the entrance to the harbour and sank the two destroyers Wilhelm Heidkamp (killing Commodore Bonte) and Anton Schmitt, heavily damaged Diether von Roeder and inflicted lesser damage on two others.

Erich Koellner was much more badly damaged, so the Germans planned—when she was repaired enough to move—to moor her at Tårstad in the same capacity as Diether von Roeder, as an immobile defence battery.

These forces arrived in the Ofotfjord on 13 April to find that the eight remaining German destroyers—now under the command of Fregattenkapitän Erich Bey—were virtually stranded due to lack of fuel and were short of ammunition.

Before the battle, Warspite launched its catapult plane (a float-equipped Fairey Swordfish, L 9767), with the crew ordered to search for German ships and to bomb any targets of opportunity.

The first lost was Erich Koellner, which tried to ambush the Allied forces but was spotted by Warspite's Swordfish and subsequently torpedoed and shelled by the destroyers and battleship.

The remaining German destroyers (Wolfgang Zenker, Georg Thiele, Bernd von Arnim and Hans Lüdemann) retreated into Rombaksfjord and were scuttled soon after.

On occasions, the entire operation was controlled directly from the German High Command in Berlin; Hitler's mood was reportedly swinging heavily and he repeatedly contemplated withdrawal.

First, the forces protecting Narvik were unable to resist the Germans due to the commanding officer—the later NS Hird commander Colonel Konrad Sundlo—refusing to fight the invaders; second, around 200 soldiers from the Narvik garrison who had escaped capture and were blocking the railway to Sweden were caught by surprise while resting at Bjørnfjell, most of the men being captured; third, I/IR12 (1st battalion of Infantry Regiment 12) sent to hold Gratangsbotn was attacked by surprise while in camp, suffering casualties that ruined its spirit and effectively knocked it out of the remainder of the campaign.

[48] Due to mounting Norwegian pressure and difficulties with bringing up supplies to the forward lying troops, the Germans abandoned Gratangsbotn and withdrew from the hill Lapphaugen and the valley Gratangsdalen, following the Battle of Gratangen.

The initial British detachment was reinforced on 28 April by a French expeditionary force (Corps expéditionnaire français en Scandinavie, CEFS), led by General Antoine Béthouart and composed of mountain troops.

Then landing craft put ashore French Foreign Legionnaires, supported by five French Hotchkiss H39 light tanks of the 342e CACC (Compagnie Autonome de Chars de Combat/ Independent Tank Company), which successfully attacked Bjerkvik,[50] the Elvegårdsmoen army camp and advanced northeast to where the Germans were withdrawing and south along the east side of Herjangsfjord.

It had been anticipated in London that as the buildup of troops in Narvik slowly continued, a corps headquarters would be needed to exercise effective control.

[53] It was clear to the Allies that once Narvik was captured, its long-term retention would depend on permanently holding the town of Bodø to the south in Nordland which was on the route of the German advance from Trondheim.

The next day, while sailing through the Norwegian Sea to return to Scapa Flow, the carrier and her escorts—the destroyers HMS Acasta and Ardent—were intercepted by the German battlecruisers Scharnhorst and Gneisenau.

The British had drafted plans to land in Narvik before the German invasion; troops and supplies had been loaded onto ships when they executed their mining operation on 8 April.

The confusion dogged the troops for weeks, men and equipment were shipped to Norway separately without clear landing sites and orders were changed while en route.

It became apparent that the Allies were confused by the many small and large fjords and bays and could not decide where it would be best to start; British, French and Polish units rapidly relieved each other which added to the lack of local knowledge.

Some of the French Foreign Legionnaires came directly from fighting in North Africa and most of the Polish officers and many of the soldiers had participated in the defence of Poland, some even in the Spanish Civil War and were highly motivated.

The reason for their defeat lay in the German plans, which made it impossible for their destroyers to retire quickly, even if they had had adequate supplies.

[citation needed] The British forces achieved an indisputable local naval victory but were unprepared to follow it up with any land operation.