The German invasion of Norway on 9 April 1940 was the first sign that the “Phoney War” period that had followed the Polish campaign of 1939 was coming to an end.
The German navy entered the Second World War with two motives for an invasion of Norway. As early as 1934 Hitler had connected the planned expansion of the German navy with the need to protect the Scandinavian ore trade. Just over half of that iron ore was shipped to Germany from Narvik, in the far north of Norway. Although the naval war staff believed that Norwegian neutrality was the best protection for the ore trade, Admiral Raeder, the commander-in-chief of the navy, favoured a more aggressive stance. His second motive for intervening in Norway was to acquire naval bases that could be used to outflank the British naval blockade of Germany. During the First World War the Royal Navy had been able to block the channel and the northern entrance to the North Sea to German shipping, and the blockade had played an important role in the final German defeat. Bases in Norway would outflank the easiest blockade route, from the Shetland Islands to the west coast of Norway.
Soon after the start of the war, Raeder suggested that German should acquire submarine bases on the Norwegian coast, possibly with the aid of the Soviet Union. The situation changed with the start of the Winter War between Finland and the Soviet Union at the end of November 1939. There was now a real chance that the British and French might occupy northern Sweden and Norway as part of an effort to help the Finns. Work began on a plan to pre-empt that move in January 1940. On 13 January, at the same time that the Naval War Staff were examining an existing army study, a Special Staff N (North) was formed within the Wehrmacht High Command to prepare an invasion plan. On 5 February they were renamed special staff Weserübung (Weser Exercise), and on 21 February General von Falkenhorst was placed in command of the operation.
Work was well under way on the planned invasion before the Altmark incident of 16 February. The Altmark had been a supply ship for the pocket battleship Admiral Graf Spee. She was attempting to return to Germany carrying prisoners of war captured by the Graf Spee, and was illegally using Norwegian waters in an attempt to sneak past the British blockade. This was a blatant breach of Norwegian neutrality, and the British responded by sending the destroyer Cossack into Norwegian waters to search the Altmark (also a breach of neutrality, but only after the Norwegians had failed to enforce that neutrality).
By this point the prospect of any Allied intervention in Finland was fading fast. Norway and Sweden had refused to take part, and before the Allies could take any direct action, negotiations began between Finland and the Soviet Union. Work still continued on the planned invasion. The directive for Weserübung was signed by Hitler on 7 March. The end of the Winter War produced mixed reactions in the German army and navy. Raeder no longer believed the British or French would land troops in northern Norway, but towards the end of March he argued that the invasion should go ahead anyway, on the grounds that it would probably been needed at some point. He had a third motive to favour the invasion, believing that the navy needed to take part in at least one major operation if it was to justify major post-war expenditure.
It is often stated that the German invasion of Norway was launched when it was because of the British operation to lay mines close to Narvik on 8 April. This is simply not the case. Operation Weserübung actually began on 11 March, when the submarines designated to watch Narvik and Trondheim left port. More submarines were dispatched on 31 March, and a final group on 6 April. The first surface ships left port on 3 April (supply ships and oil tankers). The troop transports began to sail on 6 April, and the first warships on the morning of 7 April. The first British ship involved in the mining of Narvik didn’t sail until 5 April, by which time the German operation was well underway.
The plan for Weserübung Nord (North) was undoubtedly daring. A number of German supply ships were put in place under the guise of empty ore ships returning to Narvik. Five landings were to take place on 9 April. Group 1 contained the battlecruisers Scharnhorst and Gneisenau and ten destroyers. The two battlecruisers were to take up a position to the west of Narvik, to guard against British intervention, while the destroyers carried troops to Narvik. Group 2, the cruiser Hipper and four destroyers was to attack Trondheim. Group 3, containing the light cruisers Köln and Königsberg, two auxiliary warships and a number of torpedo boats would attack Bergen. Group 4, containing the cruiser Karlsruhe two torpedo boats and a number of motor torpedo boats would attack Kristiansand. Finally Group 5, with the pocket battleship Blücher, the new heavy cruiser Lützow and the cruiser Emden would attack Oslo. Stavanger would be seized from the air, and another aerial assault would be made to assist the attack on Oslo. This first wave of the invasion would be made by the 3rd Mountain Division, the 69th Infantry Division and the 163rd Infantry Division. Three more infantry divisions, the 181st, 196th and 214th would then be either shipped or airlifted to Norway.
Britain and France were also aware of the importance of the Swedish iron ore trade, and of Narvik. Their biggest problem was that they did not want to be seen to breach Norwegian neutrality. Britain was just as big an importer of Swedish ore as Germany, all of which came via Narvik, so any plan that stopped the entire ore trade was unacceptable.
The outbreak of the Winter War between Finland and Germany’s new ally the Soviet Union briefly offered hope of a way around the neutrality problem. The only realistic way for Britain and France to get aid to Finland in any meaningful way was to use the iron ore railway from Narvik to the Baltic. It was hoped that Norway and Sweden would allow the Allies to occupy the area. This plan was approved in February 1940, but there was little evidence to support the idea that Norway or Sweden would agree to the plan. In any case the start of negotiations between the Finns and the Soviets in March 1940 removed any chance of this plan being implemented.
A more realistic plan was to lay mines in Norwegian waters, to force merchant ships out into international waters where they could be searched by the Royal Navy. This idea was first proposed by Churchill, then First Lord of the Admiralty, on 19 September, as a possibility if the Norwegians did not agree to stop the ore trade. The idea was rejected at the time. On 19 November Churchill suggested reviving the northern barrage. This was a minefield that had been laid between the Orkneys and the Norwegian coast towards the end of the First World War. This project was approved, but would take six months to prepare.
A less ambitious plan, to lay mines in the southern approaches to Narvik, was first approved in January 1940, after it was believed that the Germans had sunk three British ships in Norwegian waters. That permission was then withdrawn after strong protests from the Norwegian and Swedish governments, but in March the idea surfaced again. After delays caused by a disagreement with the French, the plan to mine the waters off Narvik (Operation Wilfred) was approved at the end of March.
The operation itself was carried out successfully early on 8 April, but by then the approaching German invasion was about to make it irrelevant. If Norway fell into German hands, then Norwegian waters would no longer be neutral, and the British would be free to attack the iron ore trade. The naval operations to support the mine laying did mean that a number of British ships were in Norwegian waters on 8 April, as the invasion fleet took up its place. This led to two clashes between British and German ships.
The first clash was between the British destroyer Glowworm and the German cruiser Hipper. The British destroyer had been detached from the forces escorting the British mine layers on 6 April. Two days later she sighted the German destroyer Bernd von Arnim. She was carrying some of the troops from the invasion force, and so turned to run back towards the support of the Hipper. The first salvo from the German cruiser hit the Glowworm. Her captain, Lieutenant-Commander Roope, decided to ram the German cruisers. Fearing a torpedo attack, the Hipper also turned to ram, but too slowly, and she was struck in the side by the Glowworm. The British destroyer then sank with heavy loss of life, while the Hipper took damage that kept her out of action throughout May.
The second came early on the morning of 9 April. Having escorted ten destroyers to Narvik, the battlecruisers Scharnhorst and Gneisenau moved north west, to take up their patrol positions. At 3.37am they were sighted by the British battlecruiser Renown. She was at sea to protect the forces that had been laying mines off Narvik. A short battle followed, fought in heavy seas and amongst snow storms, with poor visibility. The British believed they were fighting one battlecruiser and a Hipper class heavy cruiser, while the Germans thought they were being attacked by two battleships. The Renown had the better of the fight, knocking out the Gneisenau’s main armament control system and her forward turret, without taking any significant damage herself. The short battle ended with the elderly British battlecruiser chasing the two modern German ships across the northern seas. If the Germans had realised which British ship they were facing, the battle would probably have ended rather differently. The Renown was a modernised First World War battlecruiser, capable of 30.25kts, protected by 9in thick belt of armour and carrying six 15in guns. The two German ships were faster, at 32kts, better armoured, with a 13.75in thick belt and each carried nine modern 11in guns.
At full strength the Norwegian army contained 56,000 men, divided into six divisions. Four were based near to Oslo, with the 5th at Trondheim and the 6th at Narvik. When the Germans attacked on 9 April the army had not been mobilised, and although the mobilisation orders did go out on that day, by then a number of important army depots were in German hands. The Navy contained four new destroyers, one new mine layer, two old coastal defence vessels, three pre-1918 destroyers and 40 smaller vessels. The Naval Air Force possessed 26 aircraft, including six new models, while the Air Force was not much larger, with 40 aircraft, of which only 16 were new. The first wave of German troops would contain three divisions, nearly as many men as the fully mobilised Norwegian army.
The best the Norwegians could hope for was to be able to delay the Germans for long enough for British or French aid to reach them. A chance to mobilise was missed on 8 April, when the Polish submarine Orzel sank the German troop transport ship Rio de Janeiro. German survivors told their rescuers that they had been on the way to Bergen to “defend” the Norwegians against the British. This news reached Oslo on 8 April, but was dismissed, partly because the Norwegian government was distracted by the news from Narvik.
The Germans Invade - 9 April
The only real German setback on 9 April came at Oslo. There the German cruiser Blücher was sunk gunfire and torpedoes from the Norwegian fortress at Oscarborg, preventing the naval expedition from reaching the Norwegian capital. The city fell later on 9 April after an aerial assault captured Fornebu airfield, but by then King Haakon VII and the Norwegian government had escaped, ending any chance that the Norwegian campaign might have ended as quickly as the invasion of Denmark.
The attack on Kristiansand was delayed by fog, which stopped the first attempt to land at 3.45am. A second attempt was made just after 6am, but was defeated by the Norwegian gun batteries, which were now alert to the danger. However, a third attack after 11am succeeded, partly because the fog had returned and partly because the Norwegians mistook the Germans for French ships.
At Bergen the Germans came under fire from coastal gun batteries at 5.15am, and remained under fire for four hours. The Königsberg was hit three times, and received damaged that prevented her from leaving Bergen as planned.
At Trondheim the Hipper became involved in a short duel with the coastal gun batteries guarding the entrance to the fjord as she led her destroyers past them at 25kts. The city itself fell without resistance, but the airfield at Vaernes was not captured on the first day.
Narvik was defended by the two elderly coastal defence vessels Eidsvoll and Norge. The Germans sank the Eidsvoll on their way to Narvik, and the Norge in the harbour. General Dietl, commanding the forces attacking Narvik, then bluffed the Norwegian commander at Narvik, Colonel Sundlo, into surrendering with any resistance. At the end of 9 April the Germans had captured most of their main objectives.
The first Allied counterattacks were directed against the German navy. On 10 April five British destroyers attacked the ten German destroyers at Narvik (First battle of Narvik). They caught five of the German destroyers by surprise in Narvik harbour, sinking two and damaging the remaining three, before losing two destroyers themselves to a German counterattack. The remaining eight German destroyers and one u-boat were destroyed on 13 April by the battleship HMS Warspite supported by nine destroyers (Second battle of Narvik).
10 April also saw a more ominous success for the British. The cruiser Königsberg was still vulnerable at Bergen. On the day after the invasion it was attacked by ten Blackburn Skua dive bombers, based on the Orkney Islands and became the first major operational warship to be sunk by hostile aircraft.
The German Advance
The second part of the German attack began on 12 April when troops struck out in the areas around Oslo. The attack to the east forced the Norwegians up against the Swedish border, where by 15 April 3,000 men had gone into internment. The attack to the west was also successful, and by 16 April the German forces in southern Norway were in contact with each other.
The main attack was launched on 13 April. Four German battle groups struck to the north of Oslo, two over the mountains towards Bergen (making contact with troops moving east from there on 1 May) and two north beside lakes Mjösa and Randsfjord. Hamar fell on 18 April, but on 20 April the Germans came into contact with the main remaining Norwegian force at Lillehammer. This force, under the command of Major-General Otto Ruge and Major-General Hvinden Haug, hoped to hold the Germans around Lillehammer until British and French troops could recapture Trondheim and launch a counterattack.
It was soon realised that Trondheim was a crucial location. A three pronged plan was developed, calling for landings at Trondheim, Namsos to the north and Andalsnes to the south. The landing at Trondheim was cancelled on 19 April under pressure from the Joint Planning Staff, leaving only the two flank attacks.
The 146th Infantry Brigade landed at Namsos on 16-17 April. This placed them 125 miles north of Trondheim by road. They were rushed south to help the Norwegians fighting around Trondheimfjord, north of the city. On 19 April two German destroyers managed to land troops behind the most advanced British positions, and they were forced to retreat to a new line north of Steinkjer. The fighting on this front then died down, until the British troops were withdrawn on 2-3 May.
Two battalions of the 148th Infantry Brigade landed at Andalsnes on the night of 18 April. They were then rushed east to Lillehammer, arriving on the night of 19 April. There they came under Norwegian command. The Germans attacked the Allied position around Lillehammer on 32 April, and the British and Norwegians were soon forced to retreat. Reinforcements then arrived in the shape of the 15th Infantry Brigade, originally earmarked for the attack on Trondheim. They clashed with the Germans at Kvam, 55 miles north west of Lillehammer, on 25 April. The British were then forced into a slow fighting retreat back towards Andalsnes. By now the Germans had command of the air, and were threatening to make both Andalsnes and Namsos unusable. On the night of 30 April the British evacuated their troops from Andalsnes. In the aftermath of the British retreat, the remaining Norwegian forces had no choice but to surrender.
Trondheim was not the first Allied target in Norway. The Swedish ore supplies still dominated thinking, and an attack on Narvik was initially given top priority. The British expedition to Narvik left port on 11 April, but before it arrived was halved in size. Command of the expedition was divided between Admiral of the Fleet Lord Cork and Orrery, the flag officer commanding naval forces at Narvik, and Major General P. J. Mackesy, commanding the ground forces. The two men had very different ideas about the upcoming campaign – Admiral Cork wanted to launch an amphibious assault as soon as possible, to take advantage of the naval victory of 13 April. General Mackesy took a more cautious view, preferring to wait for the snows to melt before launching a careful attack on the town. The result was deadlock.
General Dietl’s small isolated garrison (2,000 soldiers and 2,500 sailors) was attacked in the mountains by the Norwegians, but hardly troubled by the British. Eventually a large French contingent arrived, under General Marie Emile Béthouart. He was far more willing to take risks, and on 13 the French Foreign Legion to part in the first opposed amphibious landing of the war, capturing Bjerkvik, at the head of Nerjangs Fjord, north of Narvik. Mackesy was then replaced by General Claude Auchinleck. By that point the German invasion of France and the Low Countries was well under way, and it was soon decided to withdraw from Narvik. Only now was Narvik attacked. On 28 May the town fell into Allied hands, to be held for just over a week. Before they left the Allies destroyed the port and the ore handling facilities, at least delaying iron ore shipments.
King Haakon was evacuated from Tromso on 7 June, and on the following day the last Allied troops left the Narvik area. On 9 June General Otto Ruge signed an armistice with the Germans, ending the fighting on land. Under the terms of the armistice most Norwegian soldiers were allowed to return home, as could any officer who agreed not to take part in the fight against the Third Reich. Ruge himself refused to sign that agreement, and was imprisoned in Königstein Castle.
In comparison with later campaigns the overall casualties in Norway were relatively low. The Germans suffered 2,700 casualties, as well as the loss of some of their most modern ships and around 200 aircraft. The Norwegians suffered 1,335 casualties, the French and Poles 550. The British suffered most heavily, taking 4,400 casualties. Nearly a third of those losses came after the end of the land campaign, when the aircraft carrier HMS Glorious was sunk by the German battlecruisers Gneisenau and Scharnhorst while returning to Britain with an escort of two destroyers.
The most important casualty of the Norwegian campaign was Neville Chamberlain. The failure of the Trondheim campaign triggered a two-day Parliamentary debate on 7-8 May. At the end of the debate Chamberlain’s majority was reduced from 213 to 81. On the following day he resigned, and on the following day Winston Churchill was asked to form a government.