When WWII commenced in 1939, Norway was in a situation which it had some experience handling. Strict neutrality had been maintained during WWI, and there was common agreement in the government led by prime minister Johan Nygaardsvold that it would be unwise to rise from a comfortable obscurity and take a stand.

This was just as well, considering the state of Norway's armed forces. The labour government that had shaped most of Norway’s policies had strong pacifistic tendencies, and defence was a post that was mostly considered as a source of funds for other projects. The army could, in theory, call upon thirty thousand men (there were 2,9 million Norwegians in 1940), although the real figure was close to seven thousand. They were armed with Krag-Jørgensen rifles, though there were not enough submachine guns or grenades to go around, and absolutely no anti-aircraft guns, armoured vehicles or tanks.

The navy had seventy smaller ships, incapable of covering the long coast, and the air force consisted of a handful of antiquated aircraft. Due to budget cuts, field manoeuvres and exercises were limited after basic training. The coastal fortresses, vital to prevent enemy access to the ports, were armed with obsolete guns and short on ammunition. Despite passionate pleas from the minister of defence, Christian Fredrik Monsen, the government had remained complacent and maintained that only by remaining harmless could Norway hope to remain neutral.

By April 1940, Germany had been at war with France and Great Britain for seven months, yet hostilities had been remarkably restrained, to say the least. Along the French-German border, only minor actions and a few long-range artillery duels punctuated an otherwise uneventful life. Only at sea were there any significant battles. Winston Churchill, then First Lord of the Admiralty and a member of the war council, wished to mine the Norwegian Leads. The Leads lie between the islands that litter the sea just outside the Norwegian coast towards the North Sea and was kept free of ice by the Gulf Stream.

A few carefully placed minefields would force the ships that carried Swedish iron ore from the port in Narvik, where it had been taken by rail from Sweden in the winter. The Swedes had their own ports, but they were frozen shut in the winter. This would force the ships into international waters, where the Royal Navy could intercept them.

Such an operation would deprive Germany of vital resources necessary to continue the war for an extended period of time. It was estimated that six out of eight million tons of iron ore that the Germans imported came from Sweden. Furthermore, Churchill also proposed that a force should land at Narvik, march to Sweden and seize the mines in Kiruna and Gällivare. This would have the added benefit of cutting off Germany from the precious Swedish ore all year.

Despite Churchill's best efforts, however, the British war council was unable to make a decision. In the end, the Leads were mined on April 8, and some forces that could be used for an expedition to Norway were being assembled. But even while the mining was carried out, German forces were on their way to Norway.

During WWI, the effective British blockade of Germany had effectively confined the German navy to its home ports. It was determined not to let that happen again, and wanted to establish bases in Norway. Hitler considered any such moves far too risky. His opinion was that if Norwegian neutrality was breached, then the British would have an excuse to move against the ships that transported ore to Germany. Two events would make him change his mind.

The first was a meeting with Vidkun Quisling. Quisling, a former major in the Norwegian army, was one of the very few representatives of a Norwegian variant of Fascism. He had funded a party called Nasjonal Samling (National Union), although he had failed to gain a single seat in parliament. Alfred Rosenberg, the Nazi party ideologue, recommended Quisling to Hitler, and a meeting ensued. Quisling insisted to the Führer that he had many sympathizers in Norway, and that it would be possible, with a little help from Nazi Germany, to establish a Fascistic government. In exchange, the Wehrmacht would be given access to bases in Norway. Hitler was impressed, but unwilling to take the risk, although he did offer to train Quisling's militia and fund the NS.

The other event took place on February 17. The Altmark, a supply ship for the Graf Spee, had taken refuge in Norwegian waters. Hidden inside of the ship were three hundred British prisoners, taken from Merchant Navy ships attacked by the Graf Spee. The Norwegian navy had inspected the ship without discovering the prisoners, and allowed it to move on. Soon afterwards, the British destroyer Cossack boarded the Altmark and liberated the sailors, causing a few German casualties in the process. Hitler took this as a sign that Norway was unwilling or unable to defend its neutrality.

In the end, the operation (with the code name Weserübung) was ready. German navy units would take key ports in Norway disguised as British ships. The troops they carried would then, supported by the Luftwaffe, hold their objectives until relieved. Some of the objectives, such as airports, would be taken by airborne assaults. Shortly before the operation started, the German ambassador would meet with the government and claim that the Germans had come to protect them from British aggression. Denmark would be occupied simultaneously. The plan would be initiated at April 9, 05:15.

By the end of April 9, the Germans had met all their objectives in Norway. Narvik, Trondheim, Bergen, Haugesund, Stavanger and Oslo (the capital) had been taken. Not everything had gone quite according to plan, though. A number of ships had been lost in engagements with the British. However, it was at Oscarsborg in the Oslo fjord that the Germans suffered their most serious setback. The heavy cruiser Blücher, together with a few smaller ships, were on their way towards Oslo, carrying troops to occupy the city and capture the government and the royal family. The defenders at Oscarsborg fortress opened fire with two of their 28 cm Krupp guns, hitting the Blücher and setting fire to the petroleum storage. Two further torpedo hits sealed Blücher's fate, and she went down with 1 600 men, among them the administrative officials and the members of the Gestapo who had been aboard. In the end, Oslo was taken by airborne troops landing later that day, but by then, the government and the royal family had fled, together with Norway's gold reserves and the secret papers from the foreign ministry.

Before they fled, the minister of defence ordered the military to mobilise. By some tragic misunderstanding, however, he apparently gave the impression that he wanted a partial mobilisation. This meant that the conscripts would receive a letter to notify them that they should report for duty. Fortunately, the foreign minister gave a quick interview before he left Oslo in which he stated that an immidiate mobilisation was under way, no doubt assuming that such was the case. At any rate, this prompted many men to report immediately, although the Germans had in several cases already captured the local army depot. Nevertheless, isolated groups of Norwegians soldiers and volunteers set about constructing roadblocks and digging trenches in the hope that they could delay the Germans long enough. They knew that the British were coming to their aid.

Throughout the invasion, the assistance Quisling had promised Hitler was conspicuously absent. Quisling himself did try to take advantage of the situation by broadcasting a speech in which he claimed to be forming a new government with himself as prime minister, and that all resistance should stop. He was completely ignored, and would not attain any power until 1943.

The German attempts to negotiate with King Haakon VII and the government met with failure. King Haakon refused to accept any government headed by Quisling, and would rather abdicate than see a man with so little public support rule the country. The king himself had scarcely any political power, but his words were a welcome source of encouragement for the government, which had been rather nervous and unwilling to resist the Germans, yet also unable to accept their terms. They sent away the German ambassador with the message that they would not surrender. Hitler was incensed when he understood that he was being defied, and ordered their elimination. Nevertheless, several other attempts to make the Norwegians change their minds were made the during following days.

The British had been caught by surprise, and spent a day discussing their alternatives. It was decided that Narvik should be taken as soon as possible. During the days following the invasion, the Royal Navy succeeded in destroying the German ships near the city and secured the waters in northern Norway, but failed to secure Narvik itself. It was decided that a combined navy and army force with the code name Avonmouth would operate in the Narvik area. In addition, two operations would be carried out in order to take Trondheim, some seven hundred kilometers south of Narvik. A group named Mauriceforce would land to the north of Trondheim and take the city with a pincer movement, while another group, named Sickleforce, would do the same from the south. If successful, the operation would cut off deny the Germans in the south any chance of reinforcing their position in Narvik.

While the Norwegian army fought to stem the tide of Germans advancing from the south, the British hurriedly loaded their equipment on to their ships. In the confusion, many formations were separated from such vital items such as anti-tank and anti-aircraft guns, ammunition, vehicles and other heavy weapons, which arrived at the wrong place or not at all.

The command of Avonmouth was split between Major-General P.J. Mackesy and Admiral of the Fleet the Earl of Cork and Orrery. These two men had been given separate briefings and had received somewhat contradictory orders, and the system of joint command would prove to paralyse them at a time when time was working against them.

In Narvik, General Dietl found himself in command of the 3rd Mountain Division and approximately two thousand sailors who had been armed with weapons from the local Norwegian army base. Demoralised by the loss of his naval assets and much of the division's supplies, Dietl considered withdrawing from the city, but decided to hang on in the hope that relief would arrive in time. By the time the British took action, he had organized a strong fighting force.

On April 14, Mackesy landed his troops at Harstad, about fourty kilometers north of Narvik. He had considered the opposition too strong for an immediate landing in the city itself, and planned to advance on the city when he had sufficient forces. Lord Cork, on the other hand, pressed for an attack on Narvik with the forces at their disposal, in the belief that they should strike before the enemy recovered after the loss of their ships. After both commanders had conferred at length with their respective superiors in London, it was decided on the 22nd that the attack would commence two days later. The preceding bombardment by all their available warships did not seem to make any visible impression on the Germans, and the attack was called off.

During he following weeks, there were several skirmishes between the British forces, which also included some French Chasseurs Alpins and the Germans, although no decisive battles took place. Avomnouth was also reinforced by some Polish units. The most effective force in existence in the Narvik area was probably the Norwegians, though. Equipped with skis and white cloaks, they were capable of greater mobility than any of their allies, with the possible exception of the French.

Narvik was finally captured on May 28, principally by the Norwegian, Polish and French forces, and the Germans were forced out of the city towards the border to Sweden. Since the British operations in the south had been called off earlier, strong German forces would eventually reach Narvik. It was unlikely that the allies could hold the city on their own. Before the withdrawal was carried, the allies used the opportunity to demolish the port facilities.

On May 25, the War Cabinet considered the situation in Norway so unfavourable that they felt that the only action left was to withdraw (the formal decision was taken a few days later). Besides, the German breakthrough in France meant that nothing could be spared for the campaign in Norway. The Norwegian government and the royal family, which had moved to Tromsø in the extreme north of Norway, accepted London's offer of exile in London, although they were appalled when they discovered that the British had been unwilling to disclose this to them until the very last moment. In fact, none of the Norwegian commanders were told until the last minute, and many of them were left in a difficult strategic situation when the allies unexpectedly took their leave. They and their men, who had been fighting continually for almost two months, were bitterly disappointed, and many felt that their allies had betrayed them.

Mauriceforce and Sickleforce experienced similar fates. None of them made it to Trondheim. Both met strong German resistance, and were at times almost continually bombed and strafed by the Luftwaffe. South of Trondheim, Sickleforce was forced to move south in order to counter strong German forces that had been pushing the Norwegians northwards. The general lack of anti-aircraft weapons and the proper equipment needed to effectively operate in the snow were probably the two most important factors which led to their strategic withdrawal in early May. For the French Chasseurs Alpins, which had great potential in the snow, it was especially unfortunate that their skis had been mislaid. Nevertheless, they were considerably better prepared than the British to fight in the snow.

The battles above have been described rather briefly, mostly because delving into details would necessitate a lot of repetition. There was little in the way of exceptional tactics or strategies involved. The problems faced in the three operations were almost identical, namely a lack of friendly air cover (with a few exceptions) and a shortage of heavy weapons. They cold weather and snow storms also hampered them, although this affected both sides. Still, the allies only had access to whatever vehicles they had managed to borrow from the Norwegians, while the Germans were better prepared in this aspect. While the Luftwaffe was unable to effectively intervene in Narvik for much of the campaign, Mauriceforce and Sickleforce bore allied soldiers fought bravely against a superior enemy that received continual reinforcements from the south, but they could not hope to prevail.

The battle for Norway was an abysmal defeat for the allies, although they had suffered remarkably few casualties. In fact, the German navy now had their bases, but a drastically weakened force to take advantage of it. The British divisions that retreated from Norway could not make it to France in time, and would be used to defend against the expected German invasion that never came. For the Norwegians, there would be five hard years until the Wehrmacht surrendered unconditionally on May 8, 1945. The incompetence of government was conveniently forgotten.

However, as every cloud has a silver lining, the German occupation of Norway gave the allies one advantage: Hitler insisted that Norway would be the stage for the Allied invasion of German-occupied Europe, partially because the Allies staged several raids on German forces stationed by the coast. At most, about three hundred thousand soldiers were kept there, among them some of the Wehrmacht's best divisions. Few of them saw any action.

Jack Adams, The Doomed Expedition (ISBN 0 7493 0282 8)
William Shirer, The Rise and Fall of the Third Reich (ISBN 0 330 70001 4)
François Kersaudy, Kappløpet om Norge (the Norwegian translation of Norway 1940) (ISBN 82-504-1754-2)