On April 9, 1940, German warships enter major Norwegian ports, from Narvik to Oslo, deploying thousands of German troops and occupying Norway. At the same time, German forces occupy Copenhagen, among other Danish cities.
German forces were able to slip through the mines Britain had laid around Norwegian ports because local garrisons were ordered to allow the Germans to land unopposed. The order came from a Norwegian commander loyal to Norway’s pro-fascist former foreign minister Vidkun Quisling. Hours after the invasion, the German minister in Oslo demanded Norway’s surrender. The Norwegian government refused, and the Germans responded with a parachute invasion and the establishment of a puppet regime led by Quisling (whose name would become a synonym for “traitor”). Norwegian forces refused to accept German rule in the guise of a Quisling government and continued to fight alongside British troops. But an accelerating German offensive in France led Britain to transfer thousand of soldiers from Norway to France, resulting ultimately in a German victory.
In Denmark, King Christian X, convinced his army could not fight off a German invasion, surrendered almost immediately. Hitler now added a second and third conquered nation to his quarry, which began with Poland.