The German Invasion of Norway. Geirr H. Haarr

of in a very short time’. A week later, on 26 March, the British Embassy in Stockholm reported an increased concentration of aircraft in northern Germany and ships in Baltic ports, which were now rapidly becoming ice free. It was added that a ‘senior naval officer in the Ministry of Defence’ had disclosed that ‘Swedish staff believe Germans are concentrating aircraft and shipping for operation which Swedish intelligence consider might consist of seizure of Norwegian aerodromes and ports. Pretext being disclosure of Allied plans of occupation of Norwegian territory, thus compelling German intervention.’⁸ Several reports followed in the coming days confirming the build-up of tension in Germany over Allied intentions in Scandinavia. On 31 March, newspaper clippings reported sources ‘in close touch with German government’ saying there was an ‘immense danger for [the] neutrals and particularly for Scandinavian countries’. The British ‘policing of Scandinavia, [with] the British Fleet controlling the Kattegat and neutral waters, through which Germany obtained her supplies from the north’, had reached a critical level and Germany now found itself ‘compelled to protect her interest, by all means at its command’.⁹

      On 3 April, the War Cabinet was notified that the War Office had received reports of troop concentrations in the Rostock area and there were several troopships in Stettin and Swinemünde, believed to be ready for an intervention in Scandinavia. The deputy chief of naval staff, Vice Admiral Tom Phillips, compiled a memorandum to Churchill and First Sea Lord Admiral Pound where he concluded: ‘The Germans are all ready for some operation against southern Scandinavia, and they may be planning to carry one out in the near future.’ It was not clear ‘whether the action is taken independently by the Germans or as a result of action we may take vis-à-vis the Norwegians’. To be on the safe side, Phillips advised that the army ‘should be instructed . . . to be prepared to improvise an expedition at the shortest notice’. It appears however, that the two lords were of the opinion that the Germans were waiting for the Allies to strike first and no recommendations were made to the War Cabinet or the CoS.¹⁰

      In an appendix to the orders issued on 5 April to the commanders of the R4 forces, copied to the War Cabinet, the CoS discusses ‘possible German operations in Norway’. It is concluded that at least four divisions were available in northern Germany, with some training in combined operations, and others could quickly be moved to the coast. Sea and air transport for these troops were abundantly available. The most likely German targets were considered to be Stavanger and Kristiansand, because of their airfields. An attack in Oslofjord was considered ‘most hazardous’, and, should the Germans decide to go for the capital, it would most likely be through the landing of troops on each side of the outer fjord. No German landings were considered at all north of Stavanger.¹¹

      In the small hours of 6 April the British vice-consul in Copenhagen, Charles Howard-Smith, reported to London that he had been informed the previous evening by the US minister, who had a well-placed neutral source, that Hitler had given ‘definite orders to send one division of ten ships to land at Narvik on 8 April, occupying Jutland on the very same day, but leaving Sweden [alone]’. In the afternoon of the same day, a supplementary telegram said the troops had actually embarked on 4 April, but there was disagreement in the military as to the prudence of the operation and they ‘hoped to have the order rescinded’.¹²

      The naval section of the Government Code and Cypher School (GC&CS) at Bletchley Park informed the Admiralty’s OIC on 7 April of a significant increase in German naval radio activity indicating several ships at sea in the Baltic and west of Denmark. The OIC had limited experience with the novel science of sigint – it was mainly run by civilian academics with little knowledge of naval matters – and, not being informed of other warning signals, did not sound the alarm.¹³

      At the RAF, an increased Luftwaffe reconnaissance activity was registered in the North Sea and Skagerrak after a period of relative inactivity. By chance, the first aerial photos of Kiel harbour were taken on the 7 April, showing numerous ships and significant activity. As there were no previous photos to compare it with, and as Scharnhorst and Gneisenau were reported in Wilhelmshaven, nothing appeared urgent to the RAF analysts – not even when subsequent reconnaissance flights in the evening reported ‘intense shipping activity and brilliantly lit wharves’ at Eckernförde, Kiel, Hamburg and Lübeck.¹⁴

      In Denmark, the British naval attaché Henry Denham heard rumours of German minesweepers off the Danish coast, and in the morning of Sunday 7 April drove south from Copenhagen to investigate. To his immense excitement he twice observed large warships heading west. Added to other information of recent German fleet movements, Denham had no doubt that this was serious and rushed back to Copenhagen. At 14:35 he reported to the Admiralty: ‘German warships Gneisenau or Blücher with two cruisers and three destroyers passed Langeland [in the] Great Belt northbound daylight today. Similar force now passing northward, off Møen. Through Sound at 11:00. Large concentration of trawlers in Kattegat.’ At 17:42, a second report from Denham stated he had had the report confirmed by the Danish Admiralty, but as the ships had not been sighted since midday, it was unclear if they had continued northwards.

      Some months later in London, Denham met his friend Captain Ralph Edwards,

      . . . who had been Duty Captain at Admiralty the evening of 7th April when my telegram, reporting enemy ships and their probable Norwegian destination, had been received. He told me he had taken it straight across to Winston Churchill who, after studying the contents, had merely remarked ‘I don’t think so.’ Months later when the two men happened to be together at sea, crossing to a Washington conference, Churchill, recognising Edwards and remembering their earlier meeting about my telegram, generously admitted his error of judgement.¹⁵

      The last entry of the Admiralty War Diary on 7 April, at 23:58, notes the naval attaché in Copenhagen having reported personally sighting the cruiser Blücher and other German warships south of Gedser on a westerly course at 14:00 and again at 17:00. The report was dismissed however, with the comment ‘evidently doing exercise with ship out of sight’.¹⁶

      Harry Hinsley, a historian and cryptanalyst who worked at Bletchley Park during WWII, concludes: ‘. . . given the organisation of intelligence and the state of its sources, . . . we can scarcely be surprised that the significance of the many indications Germany was preparing the invasion of Norway and Denmark eluded the individual intelligence bodies and the interdepartmental authorities.’¹⁷ Possibly, but a significant responsibility rests with the decision makers who failed to collate the growing information into a pertinent picture of German intentions while maintaining necessary flexibility to realise and act upon a strategic concept, differing from what they had expected. It was all the more puzzling as Plan R4 was to be initiated as soon as the Germans ‘set foot on Norwegian soil, or there was clear evidence they intend to do so’.

      Major-General Ismay, secretary of the Military Coordination Committee later wrote:

      We had suspected, that some mischief was brewing in Norwegian waters, for there had been reliable information two nights previously that a sizeable, German naval force was on the move northwards, and at the War Cabinet meeting the next morning the First Lord had reported that a few hours previously the destroyer Glowworm had signalled that she was in action against a superior force, that her signals had suddenly ceased, and that she had evidently been overwhelmed. This was confirmation that a German force was at sea, but it was thought their objective was probably limited to forestalling any action that we might take at Narvik.¹⁸

       Occupied Next Week

      On 31 March, the Swedish minister in Berlin, Arvid Richert, sent a note to Foreign Minister Christian Günther in Stockholm. The note said reliable sources had informed the embassy that troops, horses, vehicles and equipment had been embarked in fifteen to twenty-five large ships in Stettin and Swinemünde. The troops might be intended for a preventive seizure of key areas in Sweden to secure the supply of iron ore. Supplementary information over the next days confirmed the embarkation, but shifted the potential target of the operation to Norway, and held it would not be initiated without Allied provocation. Richert argued, though, that