7. While Britain and France were gathering their strength, Germany was transferring hers from the cast to the north and the west. Aerial reconnaissance provided the Allies with this information, but the process was one with which their air strength was insufficient to interfere. Before the attack was made on the west, German forces invaded Denmark and Norway. These two countries had guarded their neutrality unimpeachably and perhaps the memory of the last German war encouraged them to rely on their being left alone during the present one. Hitler, however, was determined to break the blockade if he could. To do so he needed the Atlantic seaboard, and the occupation of Norway would give it to him from the Arctic to the North Sea. So Denmark and Norway were invaded.
8. The invasion of Denmark was too swift and too rapidly successful to offer any chance of effective Allied intervention, but the Norwegians, in spite of their long inexperience of war and the surprise of the attack, put up a gallant fight to which Britain lent all the force at her disposal. The successful treachery which had quickly gained the ports of Oslo, Bergen, Trondhjem and Stavanger, together with the key airfields, coupled with the lack of Allied air cover, soon gave the Germans the advantage, and though the occupation of Narvik, the port from which the Swedish iron-ore passed to the coastal ships for Germany, was soon revenged in the gallant and destructive raid by H.M.S. Warspite and her attendant destroyers, there was eventually nothing for it but to evacuate and to concentrate all available strength in the west.
9. With the occupation of Norway and Denmark the Germans had enormously strengthened their position. They now held the entrance to the Baltic. The use of the Norwegian ports would put them in a position to strain most severely the British control of the seas between Shetland and Iceland. The airfields which were eventually to be developed would give them the power to dominate the seas in the Norwegian Arctic when the Russian campaign began.
9th April 1940 Germans invade Denmark. Copenhagen occupied.
9th April 1940 Germans invade Norway.
10th April 1940 1st Battle of Narvik. H.M. destroyers Hordy, Hotspur, Havock and Hunter destroy six enemy supply ships and an ammunition ship, and damage two destroyers.
13th April 1940 2nd Battle of Narvik. H.M. battleship Warspite and H.M. destroyers Korus, Hero, Foxhound. Kimberley, Forester, Bedouin, Punjabi, Eskimo and Cossack destroy nine enemy destroyers.
15th—18th April 1940 British Expeditionary Force lands in Norway at Namsos and Narvik.
10th June 1940 Crisis in France leads to withdrawal of the British Expeditionary Force from Norway.
