5: France and the United Kingdom notify Norway of their reservation of the right to deny Germany access to Norwegian resources.
6: British Admiralty receives a report from Copenhagen stating ten German destroyers are headed towards Narvik, but considers the possibility of such an event doubtful.
7: German vessels begin to set to sea for Operation Weserübung, some are seen by RAF reconnaissance and later attacked without effect by bombers. Home Fleet moves NNE in search of the enemy, they are joined by the 2nd Cruiser Squadron.
8: HMS Glowworm is sunk by the German cruiser Admiral Hipper after giving chase to the German destroyer Bernd von Arnim. The Polish submarine ORP Orzeł sinks the German transport Rio de Janeiro at the southern Norwegian coast.
9: Denmark is captured by the German 170th Infantry Division and German 198th Infantry Division under command of General Kaupitsch. Landings in Norway begin. Egersund is captured without resistance, as isArendal. German heavy cruiser Blücher is sunk by shore batteries along Oslofjord, and troops land further south than intended. German air-landed soldiers land at and capture the airport at Oslo. Weather slows but does not prevent successful landings at Kristiansand, while surprise paratrooper landings at Stavanger quickly secure the airfield there. Bergen and Trondheim are captured quickly. The Narvik landing force evades British naval forces and defeats the Norwegian vessels in the fjord.
10: The First Battle of Narvik occurs when a British force of five destroyers enters Ofotfjord. The Germans have ten destroyers defending and both sides lose two ships, with the German force suffering greater damage beyond that to other vessels. At Bergen, the German cruiser Königsberg is sunk by air attack. In Oslo, the Norwegian government has left, and Vidkun Quisling becomes the head of the new government.
11: Luftwaffe bombers attack the town of Nybergsund at 17:00, destroying civic buildings. It also bombed the town of Elverum, destroying the town's center and killing 41.
12: Kongsberg falls to German forces without a fight.
13: The Second Battle of Narvik occurs when a British force of nine destroyers and the battleship HMS Warspite enter Ofotfjord and destroy all eight defending German destroyers.
14: British forces land at Namsos and Harstad as Anglo-French forces prepare to launch operations against German forces at Trondheim and Narvik.
14: German Fallschirmjäger paratroopers make a combat jump at Dombås and block the rail and road network in southern Norway for five days before being forced to surrender by the Norwegian Army on 19 April.
19: The British 146th Brigade is forced to withdraw from Steinkjer by German forces.
20: German air raids ruin Namsos harbour for landing purposes. German forces moving north from Oslo reach Lillehammer and capture the town the next day.
22: German forces engage the British 148th Brigade north of Lillehammer.
23: The British 15th Brigade lands at Åndalsnes and moves to relieve the 148th Brigade.
24: German forces are besieged at Narvik, with landings planned to facilitate the capitulation of the garrison.
25: German forces successfully continue to push back Allied forces in the Gudbrandsdal north of Lillehammer. Norwegian forces conduct attacks on the Germans at Narvik.
27: Allied forces decide to withdraw from Namsos and Åndalsnes, abandoning the effort against German forces at Trondheim.
