Operation Campaign for Norway

The 'Campaign for Norway' was fought between German and Allied forces for control of the strategically important nation of Norway, which the Germans invaded in 'Weserübung' (8 April/10 June 1940).

The British and French fully appreciated the fact that Norway was strategically attractive to German ambitions as it offered ports providing superior German warship and submarine access to the North Atlantic, and at Narvik offered an ice-free port at the western terminus of the railway on which vital Swedish iron ore reached the sea for transshipment to Germany during the winter months in which the Baltic Sea was icebound.

The Allies therefore planned the 'Wilfred' and 'R4' undertakings at a time when the German invasion was feared but as yet had not started, and the battle-cruiser Renown departed the fleet base at Scapa Flow in the Orkney islands group for the Vestfjorden with 12 destroyers on 4 April. British and German naval forces met at the '1st Battle of Narvik' on 9/10 April, and the first British forces conducted the 'Sickle' landings at Åndalsnes on 13 April.

The campaign was fought until 10 June 1940 and saw the escape of King Haakon VII and his heir, the Crown Prince Olav, by sea to the UK. A British, French and Polish expeditionary force of 38,000 soldiers landed in the north. It had moderate success but made a rapid strategic retreat after the German 'Battle of France' began on 14 May with the launch of 'Gelb' and 'Sichelscnhnitt'. The Norwegian government then went into exile in London, and the campaign ended with the occupation of the entirety of Norway by Germany. A not inconsiderable number of Norwegians escaped and continued the fight overseas.

The UK and France had signed military assistance treaties with Poland and, just two days after the German 'Weiss' (i) invasion of that country on 1 September 1939, both declared war on Germany. However, neither country could mount significant offensive operations and thus period of several months, in which there were no major engagements, became known as the 'Phoney War' or 'Twilight War'. The First Lord of the Admiralty, Winston Churchill, in particular wished to move the war into a more active phase, in contrast with the thinking of the current prime minister, Neville Chamberlain.

During this time both sides wished to open secondary fronts. For the Allies, and in particular the French, this was based on a desire to avoid any repetition of the trench warfare of World War I, which had scarred the Franco/German border.

Following the outbreak of the war, the Norwegian government had mobilised elements of the Norwegian army and all but two of the Norwegian navy’s warships. The army and navy air services were also called up to protect Norwegian neutrality from violations by the warring countries. The first such violations were the sinkings in Norwegian territorial waters of several British ships by U-boats, and in the following months, aircraft from all the belligerents violated Norwegian neutrality.

Almost immediately after the outbreak of war, the British began to exert pressure on the Norwegian government to provide them with the services of the Norwegian merchant navy, being in dire need of shipping to offset the strength of the German naval forces. Following protracted negotiations between 25 September and 20 November 1939, the Norwegians agreed to charter 150 tankers, as well as other ships to a total of 450,000 gross tons. The Norwegian government’s concern for the country’s supply lines played an important role in persuading them to accept the agreement.

Although neutral, Norway was considered strategically important by each side for several reasons. First was the importance of the high-grade iron ore from Sweden, upon which German war industries were highly dependent, that was exported through the Norwegian port of Narvik. This route was especially important during the winter months when much of the Baltic Sea was frozen over. Narvik became of greater significance to the British when it became apparent that 'Catherine', a plan to gain control of the Baltic Sea, would not be realised. Grossadmiral Erich Raeder, commander-in-chief of the German navy, had pointed out several times in 1939 the danger to Germany of the UK seizing the initiative and launching its own invasion in Scandinavia, for if the powerful Royal Navy had bases at Bergen, Narvik and Trondheim, the North Sea would be virtually closed to Germany, and the Kriegsmarine would be at risk even in the Baltic.

Controlling Norway would also be a strategic asset in the 'Battle of the Atlantic'. The capture of ports would create gaps in the Allied blockade of Germany, giving German ships and submarines access to the Atlantic Ocean. These ports would allow Germany to use its albeit limited sea power more effectively against the Allies. Control of Norwegian air bases would allow German reconnaissance aircraft to operate far into the North Atlantic, while U-boats and surface warships operating out of Norwegian naval bases would be able to break the British blockade line across the North Sea and attack convoys heading to the UK.

When the USSR launched its 'Winter War' attack against Finland on 30 November 1939, the Allies found themselves aligned with Norway and Sweden in support of Finland against its significantly larger aggressor. After the outbreak of the 'Winter War', Norway mobilised land forces somewhat larger than those which had initially been considered necessary. By a time early in 1940, the Norwegian 6th Division in Finnmark and Troms fielded 9,500 troops to defend against a potential Soviet attack, positioned mostly in the eastern regions of Finnmark. Parts of the 6th Division’s forces remained in Finnmark even after the German invasion, guarding against this danger. During the 'Winter War', the Norwegian authorities secretly broke the country’s own neutrality by sending the Finns a shipment of 12 75-mm (2.95-in) pieces of artillery and 12,000 rounds, as well as allowing the British to use Norwegian territory to transfer aircraft and other weaponry to Finland.

This presented the Allies with an opportunity, for it offered them the possibility of utilising the Soviet invasion also to send troop support to occupy the iron ore fields in northern Sweden and ports in Norway. The plan, promoted by General Sir Edmund Ironside, the Chief of the Imperial General Staff, included two divisions to be landed at Narvik, five battalions somewhere in the central part of western Norway, and another two divisions at Trondheim. The French government pushed for action to be taken to confront the Germans and draw their attention away from France.

Inevitably, of course, these developments concerned the Germans. The Molotov-Ribbentrop Pact of August 1939 had placed Finland within the Soviet sphere of interest, and the Germans therefore claimed neutrality in the conflict. This policy caused a rise in anti-German sentiment throughout Scandinavia, since it was commonly believed that the Germans were allied with the Soviets. Fears began to emerge within the German high command that Norway and Sweden would then allow Allied troops to transit their territory to go to Finland’s aid.

The proposed Allied deployments never took place, following protests from both Norway and Sweden, when the issue of transfers of troops through their territory was suggested. With the Moscow Peace Treaty on 12 March 1940, the Finland-related Allied plans were dropped. The abandonment of the planned landings put immense French pressure on Chamberlain’s government, and eventually led to the Allies laying mines off the Norwegian coast on 8 April.

It was originally thought by the German high command that having Norway remain neutral was in its interest. As long as the Allies did not enter Norwegian waters, there would be safe passage for merchant vessels transporting ore via Norwegian coastal waters to Germany. Raeder, however, argued for an invasion as he believed that the Norwegian ports would be of crucial importance for Germany in a war with the UK.

On 14 December 1939, Raeder introduced Quisling, a pro-Nazi former defence minister of Norway, to Adolf Hitler. Quisling proposed pan-Germanic co-operation between Germany and Norway, and in a second meeting on 18 December, Quisling and Hitler discussed the threat of an Allied invasion of Norway. After his first meeting with Quisling, Hitler had ordered the Oberkommando der Wehrmacht to start an investigation of possible invasion plans of Norway. Meeting Quisling was central in igniting Hitler’s interest in bringing the country effectively under his control. The first comprehensive German plan for the occupation of Norway, 'Studie Nord', ordered by Hitler on 14 December, had been completed by 10 January 1940, but on 27 January Hitler ordered that a new plan, named 'Weserübung', be developed and work on this began on 5 February.

The 'Altmark Incident' occurred in the late hours of 16 February 1940 when the Royal Navy destroyer Cossack entered Norwegian territorial waters to intercept and board the German auxiliary ship Altmark in the Jøssingfjord. Altmark had spent the previous months as a fleet oiler turned prison ship for the 'pocket battleship' Admiral Graf Spee while the latter was operating as a commerce raider in the South Atlantic. When she began the return journey to Germany, Altmark was carrying 299 prisoners taken from Allied ships sunk by Admiral Graf Spee. She rounded Scotland, then entered Norwegian territorial waters near the Trondheimsfjord, flying the Reichsdienstflagge naval ensign. A Norwegian naval escort accompanied Altmark as she proceeded southward, hugging the Norwegian coast. As Altmark neared Bergen on 14 February, the Norwegian naval authorities demanded an inspection of her cargo. International law did not ban the transfer of prisoners of war through neutral waters, and the German captain refused the inspection. This led the commander in Bergen, Kontreadmiral Carsten Tank-Nielsen, to deny Altmark access to the restricted-access harbour zone. Tank-Nielsen was overruled by his superior, Viceadmiral Henry Diesen, and she was escorted through. In accordance with Norwegian neutrality regulations, government ships operated by the warring countries were forbidden from such strategically important Norwegian ports. This violation of the regulations was made as Diesen feared that the British would intercept Altmark if she was forced to sail farther offshore.

On 16 February, Altmark was spotted by three British aircraft. This led the Royal Navy to send one light cruiser and five destroyers that were patrolling nearby. Under the attack of the British destroyers Ivanhoe and Intrepid, Altmark fled into the Jøssingfjord under escort of the Norwegian torpedo boat Skarv, which was later joined in the fjord by a second such vessel, Kjell, and the patrol boat Firern. Cossack entered the fjord at 22.20, and the Norwegian vessels did not intervene when the British boarded Altmark in the late hours of 16 February. The boarding action led to the liberation of 299 Allied prisoners of war held on the German ship.

Following this, the Germans sent strong protests to Norway, which sent protests to the UK. While Norwegian, Swedish and US experts in international law described the British action as a violation of Norwegian neutrality, the UK declared that the incident was at the most a technical violation that had been morally justified.

The whole incident led the Germans to accelerate the planning for their invasion of Norway. On 21 February, General Nikolaus von Falkenhorst was placed in charge of its planning and in command of the land-based forces which would be used. The official approval for the invasion and occupation of Denmark and Norway was signed by Hitler on 1 March.

With the end of the 'Winter War', the Allies determined that any occupation of Norway or Sweden would likely do more harm than good, possibly driving hitherto neutral countries into an alliance with Germany. However, the new French prime minister, Paul Reynaud, took a more aggressive stance than his predecessor and wished to implement some form of action against Germany. Churchill was a strong agitator for action in Scandinavia as he wished to cut Germany off from Sweden and to push the Scandinavian countries to side with the UK. This initially involved the 'Catherine' plan of 1939 plan to penetrate the Baltic Sea with a naval force, but was soon changed to a plan involving the mining of Norwegian waters to prevent the shipment through Norwegian waters of iron ore shipments from Narvik and to provoke Germany into attacking Norway, where its naval forces could be defeated by the Royal Navy.

It was agreed to implement Churchill’s naval mining plan as 'Wilfred', which was designed to remove the sanctuary of safe passage by German ships through the the Leads and force them into international waters, where the Royal Navy could engage and destroy them. Accompanying this would be 'R4', an operation in which, upon the almost certain German counteraction to 'Wilfred', the Allies would then proceed to occupy Narvik, Trondheim, Bergen and Stavanger. The planners hoped that the operation would not provoke the Norwegians to resist the Allies with armed force.

The Allies disagreed over the additional 'Royal Marine', in which fluvial mines would also be placed in the Rhine river. While the British supported this operation, the French vetoed it for three months since they also depended on the Rhine river and feared German air raids on their aircraft and munitions factories. As a result of this delay, 'Wilfred', which had initially been scheduled for 5 April, was delayed until 8 April when the British agreed to undertake the Norwegian operations separately from those on the continent.

Already in low-priority planning for months, 'Weserübung' was allocated a higher priority after the 'Altmark Incident'. The goals of the German invasion were to secure the port of Narvik and the Leads for ore transport, and to control the country to prevent collaboration with the Allies. It was to be presented as an armed protection of Norway’s neutrality.

One subject debated at the same time by German strategists was the occupation of Denmark, which was seen as vital because its location facilitated greater air and naval control of the area. While some wanted to simply pressure Denmark to acquiesce, it was eventually determined that it would be safer for the operation if Denmark were captured by force.

Another matter that caused additional reworking of the plan was 'Gelb', the planned invasion of the Low Countries and northern France, an undertaking which would require the bulk of German forces. Because some elements of German military strength were needed for both invasions, 'Weserübung' could not occur at the same time as 'Gelb', and because the nights, which provided vital cover for the naval forces, were shortening as spring approached, 'Weserübung' had therefore to be undertaken before 'Gelb'. Eventually, on 2 April, the Germans set 9 April as the date of the invasion and 04.15 as the hour of the landings.

The German plan for the seizure of Norway called for the capture of six primary targets by means of amphibious landings: these targets were Oslo, Kristiansand, Egersund, Bergen, Trondheim and Narvik. Additionally, supporting Fallschirmjäger airborne forces were to be employed in smaller numbers to capture other key locations, such as airfields at Fornebu and Sola outside Oslo and Stavanger respectively. The plan was designed to ensure that the defending Norwegians would be overwhelmed rapidly, and that these vital areas be occupied before any form of organised resistance could be created and mounted. The following forces were therefore organised: Gruppe I of 10 destroyers to transport 2,000 Gebirgsjäger mountain troops commanded by Generalmajor Eduard Dietl to Narvik; Gruppe II of the heavy cruiser Admiral Hipper and four destroyers to Trondheim; Gruppe III of the light cruisers Köln and Königsberg, together with several smaller support vessels, to Bergen; Gruppe IV of the light cruiser Karlsruhe and several smaller support vessels to Kristiansand; Gruppe V of the heavy cruisers Blücher and Lützow, the light cruiser Emden and several smaller support vessels to Oslo; and Gruppe VI of four minesweepers to Egersund.

Additionally, the battle-cruisers Scharnhorst and Gneisenau were to escort Gruppe I and Gruppe II as they travelled together, and there would also be several echelons of transports carrying additional troops, fuel and equipment.

For the seizure of Denmark, two motorised brigades would capture bridges and troops; paratroopers were to capture Aalborg airfield in the north, and heavy fighters of the Luftwaffe were to destroy the Danish aircraft on the ground. While there were also several naval task groups organised for this invasion, none of them had any large ships. Unescorted troopships would transport soldiers to capture the Danish high command in Copenhagen. The following German naval forces used to invade Denmark were as organised: Gruppe VII with the 'Deutschland' class pre-Dreadnought battleship Schleswig-Holstein, two transport vessels, two minesweepers and six trawlers to land one regiment at Korsør and a company at Nyborg; Gruppe VIII of one minelayer, one icebreaker and two patrol boats to land one battalion at Copenhagen; Gruppe IX of one freighter, two tugs and seven minesweepers to land one company at Middlefart and Fredericia; Gruppe X of one escort sloop and 20 minesweepers to land two companies of the 170th Division at Esbjerg; and Gruppe XI of one minesweeper depot ship and 14 minesweepers to land one company of the 170th Division at Thyborøn.

The Germans hoped they could avoid armed confrontation with the residents of both countries, and their troops were instructed to fire only if they were themselves taken under fire.

The German forces used in the campaign totalled some 120,000 men in seven divisions and one Fallschirmjäger battalion, as well as Panzer and artillery units. Most of the Kriegsmarine’s major units were also earmarked for the campaign. The Luftwaffe’s X Fliegerkorps deployed against Norway controlled 1,000 aircraft, including 500 transport aircraft and 186 Heinkel He 111 twin-engined medium bombers.

The Norwegian armed forces fielded around 55,000 combatants in the fighting, this figure including 19,000 soldiers, mainly in six infantry divisions. In overall terms, the Norwegian army had some 60,000 trained men, typically with 3,750 men in each regiment. However, as a result of the German forces' speed and surprise, only 52,000 of the Norwegian troops saw combat. The Allied expeditionary forces numbered around 38,000 men.

The German invasion got under way on 3 April, when covert supply vessels began to leave port in advance of the main forces. The Allies initiated their plans on the following day, when 16 submarines were ordered to the Skagerrak and Kattegat to serve as a screen and give advance warning of a German response to 'Wilfred', which was launched on the following day when Vice Admiral W. Whitworth departed Scapa Flow in Renown for the Vestfjorden with 12 destroyers. On 7 April, bad weather began to develop in the region, blanketing the area with thick fog and causing rough seas, making travel difficult. Renown's force was soon caught in a heavy snowstorm, and Glowworm, one of the destroyer escorts, had to drop out of formation to search for a man swept overboard. The weather aided the Germans, providing a screen for their forces, and in the early morning they sent out Gruppe I and Gruppe II, which had the longest distance to travel.

Although the weather rendered reconnaissance difficult, the two German groups were discovered 110 miles (170 km) to the south of the Naze (the southernmost part of Norway) slightly after 08.00 by Royal Air Force patrols and reported as one cruiser and six destroyers. A bomber force despatched to attack the German ships found them 78 miles (125 km) farther to the north than they had been when first sighted. No damage was inflicted by the attack, but the German group’s strength was reassessed as being one battle-cruiser, two cruisers and 10 destroyers. Because of a strict enforcement of radio silence, the bombers were not able to report this until 17.30.

On learning of the German movement, the Admiralty came to the conclusion that the Germans were attempting to break the blockade that the Allies had imposed on Germany and to use their fleet to disrupt Atlantic trade routes. Admiral Sir Charles Forbes, commander-in-chief of the Home Fleet, was notified of this and at 20.15 the Home Fleet set out to effect an interception.

With each side unaware of the magnitude of the situation, they both proceeded as planned. Renown arrived at the Vestfjord late that night and maintained position near the entrance while the minelaying destroyers proceeded to their task. Meanwhile, the Germans launched the remainder of their invasion force. The first direct contact between the two sides occurred the next morning without either side’s intention.

Glowworm, on her way to rejoin Renown, happened to come up behind the German destroyer Bernd von Arnim and then Hans Lüdemann in the heavy fog at about 08.00 on 8 April. A skirmish immediately began and the German destroyers fled, signalling for help. The request was soon answered by Admiral Hipper, which quickly crippled Glowworm, though in the course of this action Glowworm rammed Admiral Hipper, inflicting significant damage on Admiral Hipper's starboard side. Glowworm sank. During the engagement, Glowworm had broken radio silence and informed the Admiralty of her situation. The destroyer was unable to complete her transmission, however, and all that the Admiralty knew was that Glowworm had been confronted by a large German ship, shots had been fired, and contact with the destroyer could not be re-established. In response, the Admiralty ordered Renown and her single destroyer escort (the other two had gone to refuel), to abandon her position at the Vestfjord and head to Glowworm's last known location. At 10.45, the remaining eight destroyers of the minelaying force were ordered to join them.

On the morning of 8 April, the Free Polish submarine Orzeł sank the clandestine German troop transport ship Rio de Janeiro off the southern Norwegian port of Lillesand. Discovered amongst the wreckage were uniformed German soldiers and military supplies. Although Orzeł reported the incident to the Admiralty, the latter was too concerned by the situation with Glowworm and the presumed German break-out to give it much thought and did not pass on the information. Many of the German soldiers from the wreck were rescued by Norwegian fishing boats and the destroyer Odin, and on interrogation the survivors disclosed that they were assigned to protect Bergen from the Allies. This information was passed on to Oslo, where the Norwegian parliament ignored the sinking as it was distracted by the British mining operations off the Norwegian coast.

At 14.00, the Admiralty received word that air reconnaissance had located a group of German ships a considerable distance to the west-north-west of Trondheim, bearing west. This reinforced the idea that the Germans were indeed intending a break-out, and the Home Fleet changed course from north-east to north-west again seeking to effect an interception. Additionally, Churchill cancelled 'R4' and ordered the four cruisers carrying the soldiers and their supplies to disembark their cargo and join the Home Fleet. In fact, the German ships, Gruppe II, were performing only delaying circling manoeuvres in order to approach their destination of Trondheim at the designated time.

That night, after learning of numerous sightings of German ships in the waters to the south of Norway, Forbes began to doubt the validity of the break-out notion and ordered the Home Fleet to head southward to the Skagerrak. He also ordered the battle-cruiser Repulse, along with another cruiser and a few destroyers, to head north and join Renown.

At 23:00, as Forbes was just learning of the incident with Orzeł, Gruppe V was confronted by the Norwegian patrol vessel Pol III at the entrance to the Oslofjord. Pol III quickly sent an alarm to the coastal batteries on Rauøy (Rauøy island) and opened fire on the torpedo boat Albatros with her single gun shortly before colliding with the German vessel. Albatros and two of her companions responded with anti-aircraft fire, killing the Norwegian captain and setting Pol III on fire. Gruppe V continued into the Oslofjord and cleared the outer batteries without incident. Several of the smaller German ships then broke off in order to capture the bypassed fortifications along with Horten.

This activity did not go unnoticed, and reports soon reached Oslo, leading to a midnight session of the Norwegian cabinet. At this meeting, the cabinet issued orders for the mobilisation of four of the Norwegian army’s six field divisions. The members of the cabinet failed to understand that the partial mobilisation they had already ordered would, according to the regulations of the time, be carried out in secret and without public declaration, and that the troops would be issued their mobilisation orders by post. The only member of the cabinet with in-depth knowledge of the mobilisation system, defence minister Birger Ljungberg, failed to explain the procedure to his colleagues, and was later be heavily criticised for this oversight, which led to unnecessary delays in the Norwegian mobilisation. Before the cabinet meeting, Ljungberg had dismissed repeated demands for a total and immediate mobilisation made by the chief of the general staff, Oberst Rasmus Hatledal. Hatledal had approached Ljungberg on 5, 6 and 8 April, asking the defence minister to request the cabinet issue the order for mobilisation. The issue had been discussed during the evening of 8 April, after the commanding general, Generalmajor Kristian Laake, had joined the calls for mobilisation. At that time the mobilisation had been limited to two field battalions in Østfold, further delaying the larger-scale call-up of troops. When Laake’s call for mobilisation was finally accepted some time between 03.30 and 04.00 on 9 April, Laake assumed, like Ljungberg, that the cabinet knew that they were issuing a partial and silent mobilisation. The poor communication between the Norwegian armed forces and the civilian authorities caused much confusion in the early days of the German invasion.

At about this time, farther to the north, Renown was heading back to the Vestfjord after reaching Glowworm's last known location and finding nothing. Heavy seas had caused Whitworth to sail farther to the north than normal, and he was separated from his destroyers when he encountered Scharnhorst and Gneisenau. Renown engaged the two battle-cruisers off the islands of the Lofoten archipelago, and during the short battle scored several hits on the German vessels, forcing them to flee to the north. Renown attempted to pursue, but the German warships used their superior speed to escape.

In the Ofotfjord leading to Narvik, the 10 German destroyers of Gruppe I made their approach. With Renown and her escorts earlier diverted to investigate the Glowworm incident, no British ships stood in their way, and the German warships steamed into the area unopposed. By the time they had reached the fjord’s inner area near Narvik, most of the destroyers had peeled off from the main formation to capture the outer batteries of the Ofotfjord, leaving only three to contend with Eidsvold and Norge, the two old Norwegian coast-defence ships standing guard in Narvik harbour. Although antiquated, the two coast-defence ships were quite capable of taking on the much more lightly armed and armoured destroyers. After a quick parley with the captain of Eidsvold, Kommandør Odd Isaachsen Willoch, the German ships opened fire on the coast-defence ship, sinking her after hitting her with three torpedoes. Norge entered into the fray soon after this and began to fire on the destroyers, but her gun crews were inexperienced and she failed to hit the German ships before being sunk by a salvo of torpedoes from the German destroyers.

Following the sinking of Eidsvold and Norge, the commandant of Narvik, Oberst Konrad Sundlo, surrendered the land forces in the town without a fight.

At Trondheim, Gruppe II also faced only minor resistance to the landings. In the Trondheimsfjord, Admiral Hipper engaged the defensive batteries while her destroyers sped past them at 25 kt. A well-placed shot from Admiral Hipper severed the power cables for the searchlights and thereby rendered the guns ineffective. Only one destroyer received a hit during the landing.

At Bergen, the defensive fortifications put up stiffer resistance to Gruppe III's approach, and the light cruiser Königsberg and the gunnery training ship Bremse were damaged, the former seriously. The lack of working lights reduced the effectiveness of the guns, however, and the landing ships were able to dock without much opposition. The fortifications were surrendered soon after, when Luftwaffe units arrived.

The fortifications at Kristiansand put up an even more resolute fight, twice repulsing the landing and damaging Karlsruhe, nearly causing her to run aground. Confusion soon became prevalent, however, when the Norwegians received the order not to fire on British and French ships and the Germans began to use Norwegian codes that they had captured at Horten. The Germans also used this opportunity to reach the harbour and quickly unload their embarked troops, capturing the town by 11.00.

While most of Gruppe IV was engaged at Kristiansand, the torpedo boat Greif captured Arendal without any opposition. Here the main German objective was the Norwegian end of the undersea telegraph cable to the UK.

Gruppe V encountered the most serious resistance at the inner defensive fortifications of the Oslofjord, in the vicinity of Drøbak. Blücher, leading the group of German ships, approached the forts assuming that they would be taken by surprise and not respond in a timely fashion, as had been the case with those in the outer fjord. It was not until the cruiser was at pointblank range that the Oscarsborg fortress opened fire, hitting with every shell. Within a matter of minutes, Blücher had been crippled and was burning heavily. The damaged cruiser was sunk by a salvo of antiquated, 40-year-old torpedoes launched from land-based torpedo tubes. She carried much of the administrative personnel intended both for the occupation of Norway and also for the headquarters of the army division assigned to seize Oslo. The cruiser Lützow, also damaged in the attack and believing that Blücher had entered a minefield, withdrew with Gruppe V 12 miles (19 km) southward to Sonsbukten, where she unloaded her troops. This distance delayed the arrival of the main German invasion force for Oslo by more than 24 hours, though the Norwegian capital would still be captured less than 12 hours after the loss of Blücher by troops flown into Fornebu airport near the city.

The delay imposed by the Norwegian forces gave time for the royal family and the parliament, as well as the national treasury, to be evacuated from the capital and continue to lead the fighting against the invasion force.

In the original German plan, Fornebu airport was to have been secured by paratroops one hour before the first troops arrived by air, but the initial force became lost in the fog and did not arrive. Even so, the airfield was only lightly defended and the German soldiers who did arrive captured it promptly. The Norwegian army air service’s Jagevingen fighter flight based at Fornebu airport resisted with its Gloster Gladiator single-engined biplane fighters until they had exhausted their ammunition, and then departed to whatever secondary airfields were available. The fighter unit’s ground personnel also quickly ran out of ammunition for their anti-aircraft machine guns: in the general confusion and focus on readying the fighters for action, no one had thought to issue small-arms ammunition for the ground personnel’s individual weapons. Thus resistance at Fornebu airport came to a rapid end, and the Germans' only loss was a single Junkers Ju 52/3m three-engined transport aeroplane. Norwegian attempts to mount a counterattack were half-hearted and effectively came to nothing. On learning of this, Oslo was declared an open city and soon surrendered.

For Gruppe VI at Egersund and the paratroops at Stavanger, there was no significant opposition and they quickly captured their objectives.

The German landings at Trondheim, Bergen, and Stavanger, as well as the skirmishes in the Oslofjord, soon became generally known. Not willing to disperse too widely, as the location of the two German battle-cruisers remained unknown, the Home Fleet chose to focus on nearby Bergen and despatched an attack force. RAF reconnaissance soon reported stronger opposition than anticipated, and this, along with the possibility that the Germans might be controlling the shore defences, caused them to recall the force and instead use the aircraft carrier Furious to launch torpedo bombers at the German ships. The attack never got under way, however, as Luftwaffe bombers launched an assault of their own against the Home Fleet. This attack sank the destroyer Gurkha and then forced the Home Fleet to withdraw to the north after the ships' anti-aircraft measures had proved inadequate. This German air superiority in the area led the British to decide that all southern regions had to be left to the attentions of submarines and the RAF, while surface vessels would concentrate in the north and therefore out of reach of German air power.

In addition to the German landings in southern and central Norway, the Admiralty was also informed via press reports that a single German destroyer was in Narvik. In response to this, the Admiralty ordered the 2nd Destroyer Flotilla, comprising mostly ships previously serving as escort destroyers for 'Wilfred', to engage it. This flotilla, under the command of Captain B. A. W. Warburton-Lee, had already detached from Renown during the latter’s pursuit of Scharnhorst and Gneisenau, being ordered to guard the entrance to the Vestfjord. At 16.00 on 9 April, Warburton-Lee sent an officer ashore at Tranøy, 50 miles (80 km) to the west of Narvik, and this officer learned from people of the local population that the German force was between four and six destroyers and one U-boat. Warburton-Lee sent these findings back to the Admiralty, concluding with his intention to attack the next day at 'dawn, high water', which would give him the element of surprise and protection against any mines. This decision was approved by the Admiralty in a telegram sent that night.

In the resulting '1st Battle of Narvik', of the 10 German destroyers had originally taken Narvik, only five remained in the harbour, with three others moving to the north and the remaining two to the west. Early the following morning, Warburton-Lee led Hardy and four other destroyers into the Ofotfjord, and at 04.30 arrived at Narvik harbour and entered along with Hunter and Havock, leaving Hotspur and Hostile to guard the entrance and watch the shore batteries. The fog and snow were extremely heavy, allowing Warburton-Lee’s force to approach undetected. When it arrived at the harbour itself, the British force found five German destroyers and opened fire, starting the '1st Battle of Narvik'. Warburton-Lee’s ships made three passes on the German ships, being joined after the first by Hotspur and Hostile, and sank two of the destroyers, disabled one more, and sank six tankers and supply ships. The German commander, Kommodore Friedrich Bonte, lost his life when his flagship, Wilhelm Heidkamp, was sunk.

However, Warburton-Lee made a fatal error when he decided to attack the German destroyers one last time. The German destroyers from the north and west now converged on the British force at 06.00 while the British were preparing for the final attack. Hardy was severely damaged and beached, and Warburton-Lee was killed. Hunter and Hotspur were both critically damaged, and Hotspur ran into the sinking Hunter. Hostile and Havock had meanwhile raced ahead, but turned about and came back to aid the retreat of Hotspur. The German destroyers were low on fuel and ammunition, allowing Hostile and Havock to facilitate the retreat of Hotspur.

Shortly after the '1st Battle of Narvik', two more German warships were sunk by British forces. During the night of 9/10 April, the submarine Truant intercepted and sank the light cruiser Karlsruhe shortly after she had left Kristiansand. On 10 April, the Fleet Air Arm made a long-range attack from its base at Hatston in the Orkney islands group against German warships in Bergen harbour, sinking the disabled German light cruiser Königsberg.

On 10 April, Furious and the battleship Warspite joined the Home Fleet, and another air attack was made against Trondheim in the hope of locating and sinking Admiral Hipper. This heavy cruiser had already managed to escape through the watch set up outside of the port, however, and was on her way back to Germany when the attack was launched. None of the remaining German destroyers or support ships was hit in the attack. Better luck was had in the south when the submarine Spearfish severely damaged the heavy cruiser Lützow at midnight on 11 April, putting the German ship out of commission for a year.

With it becoming more evident the German fleet had slipped out of Norwegian waters, the Home Fleet continued to the north toward Narvik in the hope of catching the remaining destroyers. En route the ships suffered further harassment from German bombers, forcing them to divert to the west, and thus away from the coast. By 12 April, the British ships were within range of Narvik and an air attack on Narvik from Furious was attempted, but the results were disappointing. Thus it was decided to send in the battleship Warspite and a powerful escort force under Whitworth’s command. On the morning of 13 April, Whitworth’s force entered the Vestfjord using Warspite's scouting aircraft to guide the way. Aside from locating two of the German destroyers, the scouting aircraft also sank a U-boat, the first such occurrence. Warspite's destroyers travelled 3.1 miles (5 km) ahead of the battleship and were the first to engage their German counterparts, which had come to meet them at the start of the '2nd Battle of Narvik'. Though neither side inflicted notable damage, the German ships were running low on ammunition and were gradually pushed back to the harbour. By that afternoon, most attempted to flee up the Rombaksfjord, the only exception being Hermann Künne, which beached herself as she made for the Herjangsfjord and was destroyed by Eskimo. Four British destroyers continued to chase the German ships through the Rombaksfjord, in which Eskimo was soon damaged by the waiting opposition. However, the German situation was hopeless as the ships had run out of fuel and ammunition, and by the time the remaining British ships arrived, the German crews had abandoned and scuttled their ships. By 18.30 the British ships were making their way out of the fjord, now clear of German ships.

The German landings for the most part achieved their goal of simultaneous assault and caught the Norwegian forces off guard, a situation not aided by the Norwegian government’s order for only a partial mobilisation. Not all was lost for the Allies though, as the defeat of Gruppe V in the Oslofjord gave a few additional hours of time which the Norwegians exploited for the evacuation of the royal family and the Norwegian government to Hamar, as noted above. With the government now fugitive, Quisling seized the opportunity to take control of a radio station and announce a coup, with himself as the new prime minister. Quisling’s coup and his list of new ministers was announced at 19.32. The Quisling coup government remained in place until 15 April, when an administrative council was appointed by the Norwegian supreme court to handle the civilian administration of the occupied areas of Norway, and Quisling resigned.

During the evening of 9 April, the Norwegian government moved to Elverum, believing Hamar to be insecure. All German demands were rejected and the 'Elverum Authorisation' was passed by the members of the parliament, giving the cabinet wide-ranging powers to make decisions until the next time the parliament could be assembled under ordinary circumstances. However, the bleakness of the situation prompted them to agree to continued negotiations with the Germans, set for the following day. As a precaution Oberst Otto Ruge, inspector general of the Norwegian infantry, set up a roadblock about 68 miles (110 km) to the north of Oslo, at Midtskogen. The Norwegian position was soon attacked by a small detachment of German troops, led by Hauptmann Eberhard Spiller, the air attaché of the German embassy, who were racing north in an attempt to capture Haakon VII. A skirmish broke out and the Germans turned back after Spiller was mortally wounded. On 10 April, the final negotiations between the Norwegians and Germans failed after the Norwegian delegates, led by Haakon VII, refused to accept the German demand for recognition of Quisling’s new government. On the same day, panic broke out in German-occupied Oslo, following rumours of incoming British bombers. In what has since been known as the 'panic day', the city’s population fled to the surrounding countryside, not returning until late the same evening or during the next day. Similar rumours led to mass panic in Egersund and other occupied coastal cities. The origins of the rumours have never been uncovered.

On 11 April, the day after the German/Norwegian negotiations had broken down, 19 German bombers attacked Elverum. The two-hour bombing raid left the town centre in ruins and 41 people dead. On the same day, 11 Luftwaffe bombers also attacked the town of Nybergsund, in an attempt to kill the Norwegian king, Crown Prince Olav and the cabinet.

One of the final acts of the Norwegian authorities before they dispersed was the 10 April promotion of Ruge to the rank of generalmajor and his appointment to the position of commanding general of the Norwegian army, responsible for overseeing the resistance to the German invasion. Ruge replaced the 65-year-old Laake as commanding general, the latter having been heavily criticised for what was considered to be passive behaviour during the initial hours of the invasion. Elements in the Norwegian cabinet considered Laake to be a defeatist. Following the appointment of Ruge, the Norwegian attitude became clear as orders were issued to mandate the halting of the German advance. With the Germans in control of the largest cities, ports and airfields, as well as most of the arms depots and communication networks, repulsing them outright was clearly impossible, and Ruge decided instead that his only chance lay in playing for time, stalling the Germans until reinforcements could arrive from the UK and France.

On 11 April, after receiving reinforcements in Oslo, the offensive of von Falkenhorst’s Armeegruppe XXI began with the object of linking Germany’s scattered forces before the Norwegians could effectively mobilise or any major Allied intervention could take place. von Falkenhorst’s first task was to secure the Oslofjord area, then to use Generalmajor Richard Pellengahr’s 196th Division and Generalmajor Erwin Engelbrecht’s 163rd Division to advance to the north to establish contact with the forces at Trondheim.

As the nature of the German invasion became apparent to the British military, it began to make preparations for a counter-attack. Dissension amongst the various branches was strong though, as the British army, after conferring with Ruge, wanted to assault Trondheim in central Norway while Churchill insisted on reclaiming Narvik. It was decided to send troops to both locations as a compromise, and Admiral the Lord Cork and Orrery was placed in overall command of the Allied operations.

After the appointment of Ruge as commanding general on 10 April, the Norwegian strategy was to fight delaying actions against the Germans advancing northward from Oslo to link with the invasion forces at Trondheim. The main aim of the Norwegian effort in eastern Norway was to give the Allies enough time to recapture Trondheim, and start a counter-offensive against the German main force in the Oslo area. The region surrounding the Oslofjord was defended by the 1st Division, commanded by Generalmajor Carl Johan Erichsen. The rest of the region was covered by the 2nd Division, commanded by Generalmajor Jacob Hvinden Haug. As the Norwegians had been prevented from mobilising in an orderly fashion by the rapidity of the German invasion, it was improvised Norwegian units which were committed to action against the Germans. Several of the units facing the German advance were led by officers especially selected by Ruge to replace commanders who had failed to show sufficient initiative and aggression in the early days of the campaign. The German offensive aimed at linking their forces in Oslo and Trondheim began on 14 April with an advance to the north from Oslo toward the Gudbrandsdalen and Østerdalen valleys. Hønefoss was the first town to fall to the advancing German forces, and it was to the north of Hønefoss that the Germans began meeting Norwegian resistance, first in the form of delaying actions and later of units fighting organised defensive actions. During intense fighting with heavy casualties on both sides, the infantry of the 6th Regiment blunted the German advance at the village of Haugsbygd on 15 April. The Germans broke through the Norwegian lines at Haugsbygd only on the following day after making their first use of armour in Norway. Lacking anti-tank weapons, the Norwegian troops could not hold back the German attack.

The basis for the Norwegian strategy had already started to collapse by 13/14 April, when the 3,000 troops of the 1st Division in Østfold crossed the Swedish border without orders and were interned by the neutral Swedes. On the same day that the 1st Division began crossing into Sweden, the two battalions of the 3rd Regiment at the Heistadmoen army camp in Kongsberg capitulated. The 3rd Division, commanded by Generalmajor Einar Liljedahl and tasked with defending southern Norway, surrendered to the Germans in Setesdal on 15 April, having seen no action up to that point: some 2,000 soldiers marched into captivity. With the abandonment on 20 April of the French and British plans for recapturing the central Norwegian city of Trondheim, Ruge’s strategy became impractical.

With the ending of the Allied plans for recapturing Trondheim, British forces which had been landed at Åndalsnes moved into eastern Norway. By 20 April three British half-battalions had moved as far south as Fåberg, near Lillehammer. The main British units deployed to eastern Norway in April 1940 were the territorial forces of Brigadier H. De R. Morgan’s 148th Brigade and the regular forces of Brigadier H. P. M. Berney-Ficklin’s (from 22 April Brigadier H. E. F. Smyth’s and from 25 April Lieutenant Colonel A. L. Kent-Lemon’s) 15th Brigade. In a series of battles with Norwegian and British forces over the next weeks the Germans pushed northward from Oslo, their main effort directed up the Gudbrandsdal valley. Particularly heavy fighting took place in places such as Tretten, Fåvang, Vinstra, Kvam, Sjoa and Otta. In the 'Battle for Kvam' on 25/26 April, the British managed to delay the German advance for two days in heavy fighting. Other German units broke through the Valdres and Østerdalen valleys, in the former case after heavy fighting and an initially successful Norwegian counterattack.

During their advance to the north from Oslo, the Germans regularly broke down Norwegian resistance through the use of pinpoint air attacks. Junkers Ju 87 single-engined dive-bombers proved particularly effective in demoralising Norwegian troops opposing the advance, and the Norwegians' almost complete lack of anti-aircraft weapons allowed the German aircraft to operate with near impunity. Likewise, when the Germans employed armoured vehicles, the Norwegians had no effective countermeasures. The British No. 263 Squadron established a base on the frozen lake Lesjaskogsvatnet on 24 April to challenge German air supremacy, but many of the squadron’s aircraft were destroyed by German bombing on 25 April. The four Gladiator fighters which survived to be evacuated to Setnesmoen army base near Åndalsnes were out of operation by the end of 26 April. Setnesmoen was bombed and knocked out by the Luftwaffe on 29 April.

After their capture of Kristiansand on 9 April, the battalion-strong German invasion force in southern Norway permitted the evacuation of the civilian population from the city. At the same time the Germans moved to secure the areas surrounding Kristiansand. After several days of confusion and episodes of panic among the Norwegian troops, despite the complete absence of fighting, the 2,000 men of the defending 3rd Division in Setesdal surrendered unconditionally on 15 April.

The important western cities of Bergen and Stavanger were captured by the Germans on 9 April. Some 2,000 German soldiers occupied Bergen and seized the local Norwegian arms depots. The small Norwegian infantry forces in Bergen retreated to the east, blowing up two railway bridges and sections of road after them. Despite the loss of the cities, the regional commander, Generalmajor William Steffens, commander of the 4th Division, ordered a total mobilisation and during the middle period of April, the 6,000-strong Norwegian 4th Division, responsible for the defence of western Norway, was mobilised around the town of Voss in Hordaland. The 4th Division was the only military district outside of northern Norway to be mobilised both completely and in an orderly fashion. The 4th Division managed to repulse the initial German push along the Bergen Line railway line connecting western and eastern Norway.

After troops of the 5th Division, father to the north, had covered the British landings at Åndalsnes, Steffens planned an offensive aimed at recapturing Bergen. To achieve this, the 4th Division had a total mobilised strength of 6,361 men with 554 horses. Steffens’a plans were made redundant on 1§6 April, when Ruge ordered most of the division’s forces to be redeployed to Valdres and Hallingdal in order to reinforce the main front in eastern Norway. The focus of the remaining forces in western Norway became to prevent the Germans from advancing from the area around Bergen. Norwegian naval forces, organised into three regional commands by Tank-Nielsen, prevented German intrusions into the Hardangerfjord and Sognefjord. In total the Norwegian navy operated some 17 or 18 warships and five or six aircraft in western Norway following the German capture of Bergen. After the Luftwaffe had bombed and severely damaged Voss and the surrounding countryside on 23/25 April, inflicting civilian casualties, the Germans captured the town on 26 April.

After the fall of Voss, Steffens evacuated the remnants of his force to the north, evacuating the southern side of the Sognefjord on 28 May (except for a small contingent at Lærdal). Steffens established his own headquarters at Førde and prepared for the further defence of Sogn og Fjordane. However, on 30 April there arrived a message from Ruge telling of the evacuation of all Allied troops, the king and the army command, from southern Norway. With no help forthcoming from either Allied or Norwegian forces, on 1 May Steffens ordered his troops to disband. The advancing German forces were informed of the whereabouts of the Norwegian troops, and agreed to let them disband unmolested. On the night of 1/2 May, Steffens left for Tromsø with three naval aircraft, effectively ending the campaign in the region. No Allied land troops had been involved in the fighting in Hordaland and Sogn og Fjordane. Another two aircraft flew to the UK. Although the Norwegian navy’s ships in western Norway were ordered to evacuate to the UK or northern Norway, only Bjerk, an auxiliary vessel, sailed to the UK and Steinar to northern Norway. The remaining ships were either prevented from leaving as a result of the desertions of most of their men, or were commanded by officers who chose to disband their crews rather than risk them in passages voyages to Allied-controlled territory. The last Norwegian forces in western Norway disbanded in Florø on 18 May.

The original plan for the campaign in central Norway called for a three-pronged attack against Trondheim by Allied forces while the Norwegians contained the German forces to the south. This 'Hammer' envisaged the landings of Allied troops at Namsos to the north ('Maurice' Force), Åndalsnes to the south ('Sickle' Force) and around Trondheim itself ('Hammer' Force). This plan was quickly changed, however, as it was felt that a direct assault on Trondheim would be too risky, and thus only the northern and southern forces would be used.

In order to block the expected allied landings the Oberkommando der Wehrmacht ordered a Fallschirmjäger company to make a combat drop on the railway junction of Dombås in the north of the Gudbrandsdal valley. The force landed on 14 April and succeeded in blocking the road and rail network in central Norway for five days before being forced to surrender on 19 April.

A British vanguard force arrived at Åndalsnes on 12 April. The main landing of 'Sickle' Force, comprising primarily the British 148th Brigade and commanded by Major General B. C. T. Paget, took place on 17 April and was facilitated by the successful Norwegian mobilisation in the area.

In the late hours of 14 April, 'Maurice' Force, comprising primarily of Brigadier C. G. Phillips’s British 146th Brigade and commanded by Major General A. Carton de Wiart made their initial landings at the Norwegian port town of Namsos. During its passage to Norway, the force had been transferred to destroyers instead of bulky transport ships as a result of the narrowness of the fjord leading to Namsos, and in the confusion of the transfer a great quantity of supplies and even the brigade commander were misplaced. Another problem for 'Maurice' Force was the lack of air support and effective anti-aircraft defences, something of which the Luftwaffe took full advantage. On 17 April the force moved forward from Namsos to positions around the village of Follafoss and the town of Steinkjer. French troops arrived at Namsos late on 19 April. On 20 April German aircraft bombed Namsos, destroying most of the buildings in the town centre, and large portions of the supply storage for the Allied troops, leaving Carton de Wiart without a base. Even so, he moved some 80 miles (130 km) inland to Steinkjer and linked with the Norwegian 5th Division. Constant aerial harassment prevented any kind of offensive, however, and on 21 April 'Maurice' Force came under attack by Generalmajor Kurt Woytasch’s 181st Division from Trondheim. Carton de Wiart was forced to fall back by this assault, leaving Steinkjer to the Germans. On 21 and 22 April Steinkjer was bombed by the Luftwaffe, leaving four-fifths of the town in ruins and more than 2,000 people homeless. By 24 April Steinkjer and the surrounding areas had been occupied by the Germans.

By 28 April, with both its forces checked by the Germans, the Allied leadership decided to withdraw all British and French forces from the southern and central regions of Norway. The Allied retreat was covered by Norwegian forces, which were then demobilised so that the men would not be taken prisoner by the Germans. On 30 April the Germans advancing from Oslo and Trondheim linked.

On 28 and 29 April the undefended port town of Kristiansund had been heavily bombed by the Luftwaffe, as was the nearby port of Molde, which functioned as the headquarters of the Norwegian government and the king. The town of Ålesund had also suffered heavily from German bombing during the last days of April.

'Sickle' Force managed to return to Åndalsnes and escape by 02.00 on 2 May, as mere few hours before Pellengahr’s 196th Division captured the port. This western Norwegian port had been subjected to heavy German bombing between 23 and 26 April, and had been burning until 27 April. The village of Veblungsnes and the area around Åndalsnes railway station suffered particularly heavy damage. By the time the Germans arrived, some four-fifths of Åndalsnes lay in ruins. 'Maurice' Force, its convoys delayed by thick fog, was evacuated from Namsos on 2 May, though two of the ships, the French destroyer Bison and the British destroyer Afridi, were sunk by Ju 87 dive-bombers.

Organised Norwegian military resistance in the central and southern parts of Norway ceased on 5 May with the capitulation of the forces fighting at Hegra in Sør-Trøndelag and at Vinjesvingen in Telemark.

The failure of the central campaign was one of the direct causes of the so-called Norway debate, which resulted in the resignation of Chamberlain as the British prime minister and the appointment of Churchill as his successor.

After being evacuated from Molde during German air attacks on 29 April, Haakon VII and his government had reached Tromsø in northern Norway by 1 May, and for the remaining weeks of the 'Campaign for Norway' Tromsø was the de facto capital of Norway and the headquarters of the king and cabinet.

In northern Norway the 6th Division, commanded by Generalmajor Carl Gustav Fleischer, faced the German invasion forces at Narvik. Following the German invasion, Fleischer became the commander-in-chief of all the Norwegian forces in northern Norway. The Norwegian counter-offensive against the Germans at Narvik was hampered by Fleischer’s decision to retain significant forces in Eastern Finnmark to guard against a possible Soviet attack in the far north.

Along with the Allied landings at Åndalsnes and Namsos, aimed at the recapture of Trondheim, further Allied forces were deployed to the north of Norway for the task of recapturing Narvik. Like the campaign in the south, the Narvik expedition faced numerous obstacles. One of the first problems faced by the Allies was the lack of any unified, or indeed organised, command. The naval forces in the area were led by Admiral of the Fleet W.H. D. Boyle, 12th Earl of Cork and Orrery, who had been ordered to rid the area of the Germans as soon as possible. By contrast, the commander of the ground forces, Major General P. S. Mackesy, was ordered not to land his forces in any area strongly held by the Germans and to avoid damaging populated areas. The two commanders met on 15 April to determine the best course of action, Cork arguing for an immediate assault on Narvik and Mackesy countering that such a move would lead to heavy casualties for his attacking troops. Cork eventually conceded to Mackesy’s opinion.

Mackesy’s force was originally codenamed 'Avon' Force, later 'Rupert' Force, which comprised ted of Brigadier W. Fraser’s 24th Guards Brigade and French and Free Polish units led by Général de Brigade Antoine Béthouart. The main force began landing at Harstad, a port town on the island of Hinnøya, on 14 April. The first German air attacks on Harstad began on 16 April, but anti-aircraft defences prevented serious damage until a raid on 20 May destroyed oil tanks and civilian houses, and another raid on 23 May hit Allied shipping in the harbour. On 15 April, the Allies scored a significant victory when the British destroyers Brazen and Fearless, which were escorting the NP.1 troop-carrying convoy, forced U-49 to surface and scuttle in the Vågsfjorden. Found floating around the sinking U-boat were documents detailing the dispositions, codes and operational orders of all U-boats in the Norwegian operational area, providing the Allies with an efficient and valuable tool when planning troop and supply convoys to the campaign in northern Norway.

After the Allied failure in central Norway, more preparation was given to the northern forces. Air cover was provided by two squadrons of carrier-transported fighters operating from Bardufoss air base: these were the re-equipped No. 263 Squadron RAF with Gladiator biplane fighters and No. 46 Squadron with Hawker Hurricane single-engined monoplane fighters.

As part of the Allied counter-offensive in northern Norway, French forces made an amphibious landing at Bjerkvik on 13 May. The naval gunfire from supporting Allied warships destroyed most of the village and killed 14 civilians before the Germans were dislodged.

While the Norwegian and Allied forces were advancing at Narvik, German forces were moving swiftly northward through Nordland to relieve the besieged troops of Generalmajor Eduard Dietl’s 3rd Gebirgsdivision. The captured Værnes air base near Trondheim was rapidly expanded and improved to provide the Luftwaffe with a base from which to support the Narvik sector. As the German forces moved to the north, they also gained control of the basic facilities at Hattfjelldal airfield to support their bomber operations.[91]

Late in April, 10 'independent companies' had been formed in the UK under the command of Lieutenant Colonel C. Gubbins. On 2 May, four of these companies were formed into 'Scissors' Force, under Gubbins, and despatched to forestall the Germans at Bodø, Mo-i-Rana and Mosjøen. Although they ambushed the leading German units in the srea to the south of Mosjøen, they were outmatched by the German main body and were withdrawn to Bodø, which was to be defended by the 24th Guards Brigade. As the 24th Guards Brigade moved to Bodø, the destroyer Somali, which was carrying Fraser, was bombed and was forced to return to the UK. Gubbins, with the acting rank of colonel, assumed command of the brigade. On 15 May the troop ship Chrobry, carrying the 1/Irish Guards, was bombed, with heavy casualties to the troops, and two days later the cruiser Effingham went aground while carrying much of the equipment of the 2/South Wales Borderers. Both battalions returned to Harstad to reform and to be re-equipped before setting out again for Bodø.

As the Germans advanced northward from the railhead at Mosjøen, the garrison of Mo-i-Rana (a mixed force based on the 1/Scots Guards) withdrew on 18 May, too precipitately in Gubbins’s opinion. The commanding officer of the Scots Guards, Lieutenant Colonel T. B. Trappes-Lomax, continued to retreat despite orders to hold successive positions and this, in combination with the delayed arrival of the rest of the brigade, left Gubbins no time to prepare a defensive position at Storjord. The brigade withdrew under heavy pressure across the Skjerstadfjord on 25 May, covered by a rearguard from the 1/Irish Guards and several of the independent companies under Lieutenant Colonel H. Stockwell.

During the evening of 27 May, Bodø was bombed and strafed by the Luftwaffe. The bombing destroyed the recently constructed improvised airstrip, the radio station and 420 of the town’s 760 buildings, killing 15 people and leaving a further 5,000 homeless. Gubbins’s force was evacuated from Bodø between 30 May and 2 June. During these three days, low cloud prevented the Luftwaffe from intervening. The improvised airstrip hit during the 27 May air raid fell into German hands, providing the Germans with an air base much closer to Narvik, and this was of great significance for the continued German advance to the north.

On 28 May, one Norwegian and two French battalions attacked and recaptured Narvik from the Germans. To the south of the town, Free Polish troops advanced eastward along the Beisfjord. Other Norwegian troops were pushing the Germans back toward the Swedish border near Bjørnfjell. However, the German invasion of France and the Low Countries had immensely altered the overall situation of the war and the importance of Norway was considerably lessened. On 25 May, three days before the recapture of Narvik, the Allied commanders had received orders to evacuate their forces from Norway. The attack on Narvik was in part carried out to mask from the Germans the Allies' intention of leaving Norway. Shortly after 28 May, when the Allies recaptured Narvik, the town was bombed and heavily damaged by the Luftwaffe.

'Alphabet', the Allied general retreat from Norway, had been approved on 24 May. Among those who argued against the evacuation was Churchill, who later expressed the opinion that the decision had been a mistake. The Norwegian authorities were informed of the decision only on 1 June. After a meeting on 7 June, at which the decision to carry on the fight abroad was made, Haakon VII, Crown Prince Olav and the Norwegian cabinet left Norway on the British heavy cruiser Devonshire and went into exile in the UK. Without supplies from the Allies, the Norwegian army would soon have been unable to continue the fight. Both the king and the crown prince had considered the possibility of remaining in Norway, but had been persuaded by the British diplomat Cecil Dormer to follow the government into exile. The crown prince suggested that he should remain and assist the Administrative Council in easing the effects of the occupation, but as a result of the king’s elderly age it was decided that they both had to go into exile, in order to avoid complications should the king die while abroad. By 8 June, after destroying railway lines and port facilities, all Allied troops had been evacuated. The Germans had launched the 'Juno' (i) naval operation to relieve pressure on Narvik’s beleaguered garrison and, after discovering the evacuation, shifted the mission to a hunt, which subsequently sank two British destroyers and the aircraft carrier Glorious. Before the British warships were sunk, however, the destroyer Acasta torpedoed and damaged Scharnhorst. Shortly after the encounter the British submarine Clyde intercepted the German ships and torpedoed Gneisenau, causing severe damage.

The Norwegian forces on the mainland capitulated to the Germans on 10 June after units fighting on the front had been ordered to disengage in the early hours of 8 June. Fighting ceased at 00.00 on 9/10 June. The formal capitulation agreement for forces fighting in mainland Norway was signed at the Britannia Hotel in Trondheim at 17.00 on 10 June 1940, Oberst­løitnant Ragnvald Roscher Nielsen signing for the Norwegian forces and Oberst Erich Buschenhagen for the German side. A capitulation agreement for the Norwegian forces fighting at Narvik was also signed on the same day, at Bjørnfjell. The signatories of this agreement, the last local capitulation of Norwegian troops during the campaign, were Dietl for the Germans and Oberst­løitnant Harald Wrede Holm for the Norwegians. The 62-day campaign made Norway the country to withstand a German invasion for the longest period of time, aside from the USSR.

With the capitulation of Norway’s mainland army, the German occupation of the country began. Although the Norwegian regular forces in mainland Norway laid down their arms in June 1940, there was a fairly prominent resistance movement, which proved increasingly efficient during the later years of occupation. The resistance to the German occupation began in the autumn of 1940, steadily gaining strength and becoming better organised. Despite Gestapo infiltration and destruction of many of the early organisations, the resistance movement survived and grew. The last year of the war saw an increase in sabotage actions by the exile government-aligned Norwegian resistance organisation Milorg, although the organisation’s main goal was to retain intact guerrilla forces to aid an Allied invasion of Norway. In addition to Milorg, many independent, mostly communist, resistance groups operated in occupied Norway, attacking German targets without co-ordinating with the exiled Norwegian authorities.

The civilian side of the German occupation of Norway was organised through the establishment of the Reichskommissariat Norwegen, led from 24 April by Josef Terboven. The Germans attempted to make the exiled Norwegian authorities irrelevant, and especially targeted the king. Weeks after the end of the 'Campaign for Norway', the Germans pressured the presidency of the Norwegian parliament to issue a request that Haakon VII abdicate. On 3 July Haakon VII turned down the request, and on 8 July gave a speech on BBC Radio proclaiming his answer. 'The King’s No', as it became known, encouraged resistance to the occupation and its Norwegian collaborators. The Administrative Council functioned until 25 September, but after that date the Germans' Norwegian partner was the Quisling fascist régime in one form or another.

The Norwegian navy and air force were re-established in the UK on the basis of the forces' remnants saved from the 'Campaign for Norway'. The revived forces soon saw extensive combat in the convoy battles of the North Atlantic and in the air war over Europe, and their ranks were swelled by a steady trickle of refugees making their way out of occupied Norway, and their equipment brought up to standard by British and US aircraft and ships. From a force of 15 ships in June 1940, the Norwegian navy had expanded to 58 warships by the end of World War II in Europe. The ships were manned by around 7,000 men and, in all, 118 warships had been under Norwegian command at one time or another during the war years.

Norwegian squadrons flew with RAF Fighter and Coastal Commands. The Norwegian-manned Nos 331 Squadron and 332 Squadrons operated Hurricane and Supermarine Spitfire single-engined fighters. The naval Nos 330 and 333 Squadron flew Northrop N-3PB floatplane patrol bombers, Consolidated PBY Catalina twin-engined and Short Sunderland four-engined flying boats, and de Havilland Mosquito twin-engined fighter-bombers. Individual Norwegians also flew with British air units. In November 1944 the Norwegian naval air service and army air service, having been under a unified command since March 1941, were amalgamated to form the Royal Norwegian Air Force, which at the end of the war had some 2,700 personnel.

A Norwegian army of some 4,000 men was also re-established in Scotland. However, with the exception of a small number of special forces, it saw little action for the rest of the war. A reinforced company from the Norwegian army participated in the liberation of Finnmark during the winter of 1944/45. Finnmark and the northern parts of Troms county had been forcibly evacuated by the Germans in a scorched-earth operation following the Soviet forces' 'Petsamo-Kirkenes Offensive Operation' against occupied Finnmark in October 1944. The offensive had captured the north-eastern town of Kirkenes from the occupying German forces. After the arrival of the 300 troops from Scotland, further troops were moved in from Sweden and still more were mobilised locally. At the end of the war, the Norwegian forces in Finnmark totalled 3,000 men, and in the course of this operation there were some minor skirmishes with German rear guards and patrols.

In neutral Sweden there was also a Norwegian build-up of forces in the last two years of the war through the so-called 'police troops' established with the support of the Swedish authorities. The term 'police' served as a cover for what in reality was pure military training of a force mustering around 13,000 well trained and equipped troops by VE-Day. In 1945 around 1,300 'police troops' took part in the Liberation of Finnmark.[110]

Aside from the regular Norwegian forces, the main armed resistance movement in Norway, the exile government-controlled Milorg, fielded some 40,000 combatants at the end of the war. In November 1941 the Milorg had been declared by the exiled Norwegian government to be the fourth branch of the Norwegian armed forces.

The German official casualty list for the 'Campaign for Norway' totalled 5,296 men including 1,317 killed on land and 2,375 lost at sea; 1,604 men were listed as wounded.

The German losses at sea were heavy, with the sinking of one of the Kriegsmarine’s two heavy cruisers, two of its six light cruisers, 10 of its 20 destroyers and six U-boats. With several more ships severely damaged, the German surface fleet had only three cruisers and four destroyers operational in the immediate aftermath of the 'Campaign for Norway'. Two torpedo boats and 15 light naval units were also lost during the campaign, and two battle-cruisers and two cruisers were damaged.

German official sources give the number of German aircraft lost during the 'Campaign for Norway' as 90, with other estimates ranging as high as 240.

In transport ships and merchant vessels, the Germans lost 21 ships at 111,700 tons, around 10% of what they had available at the time.

The Norwegian and Allied casualties of the 'Campaign for Norway' totalled some 6,602. The British lost 1,869 killed, wounded and missing on land and about 2,500 at sea, while the French and Polish lost 533 killed, wounded and missing. On the Norwegian side there were around 1,700 casualties, of whom 860 were killed. Some 400 Norwegian civilians were also killed, mostly in German bombing raids, but about 60 of the civilians killed were shot by German soldiers during the fighting in eastern Norway, many in summary executions.

On the naval side of the Norwegian casualties, the Norwegian Nnvy, fielding 121 mostly outdated ships at the outset of the German invasion, was virtually destroyed during the campaign. Only 15 warships, including a captured German fishing trawler, with some 600 men had managed to flee to the UK by the end of the fighting. The remaining Norwegian naval vessels were sunk in action, scuttled by their own crews, or captured by the Germans. Among the warships sunk in action during the campaign were two coast-defence ships and two destroyers. Seven torpedo boats were also sunk or scuttled, while the remaining 10 were captured by the Germans. Only one of the nine Norwegian submarines managed to escape to the UK, the other eight being scuttled or captured. Some 50 captured Norwegian naval ships were later pressed into service by the Kriegsmarine.

The British lost one aircraft carrier, two cruisers, seven destroyers and one submarine, but with their much larger fleet could absorb the losses to a much greater degree than Germany. The French lost the destroyer Bison and one submarine during the campaign, and one cruiser severely damaged. The exiled Polish navy lost the destroyer Grom and the submarine Orzeł.

While the British lost 112 aircraft during the campaign, the Norwegians lost all their aircraft except a few which were evacuated to the UK or flown to neutral Finland.

The combined total loss of Norwegian and Allied merchant ships and transports was some 70 vessels.

In overall terms, the 'Campaign for Norway' was a decisive victory for Germany. At sea, however, the invasion proved a temporary setback. For the Kriegsmarine the campaign led to heavy losses, leaving it with a surface force of one heavy cruiser, two light cruisers and four destroyers as operational units. This left the navy weakened during the summer months when Hitler was pursuing plans for the possible 'Seelöwe' invasion of the UK. The greatest cost of the campaign on land was the subsequent need to keep most of the invasion troops in Norway for occupation duties and thus unavailable for service on other fronts.

Through the Norwegian government’s Nortraship system, the Allies also gained the services of the Norwegian merchant navy, the fourth largest in the world. The 1,028-ship strong Nortraship was established on 22 April at a government meeting at Stuguflåten in Romsdal, and comprised some 85% of the pre-war Norwegian merchant fleet, the remaining 15% having been in Norway when the Germans invaded and been unable to escape. The Nortraship vessels were crewed by 27,000 sailors. In total, 43 Norwegian ships were sunk during the 'Campaign for Norway', while another 29 were interned by the neutral Swedes. Nortraship gave the Norwegian government in exile economic independence and a basis for continued resistance from abroad.

The Allies achieved a partial success at Narvik. The Germans had destroyed much of the port facilities there before their loss of the city on 28 May, and shipping from the port was stopped for a period of six months, although the Allies had believed it would be out of operation for a year.

The German occupation of Norway was to prove a thorn in the side of the Allies during the next few years. Bombers based at Sola had a round trip of about 570 miles (920 km) to Rattray Head in north-east Scotland, instead of a round trip of about 870 miles (1400 km) from the island of Sylt, the nearest airfield on German soil, while the east of Scotland and coastal shipping suffered from bombing raids, most from Norway, until 1943. After the fall of Norway, Scotland (especially the fleet bases at Scapa Flow and Rosyth) were seen as much more vulnerable to a diversionary assault by air- and sea-borne troops. German commerce raiders used Norway as a staging base to reach the North Atlantic. After Germany invaded the USSR in 1941, air bases in Norway were also used to interdict the Allied Arctic convoys to Murmansk and Arkhangyel’sk, inflicting severe losses on shipping.