However, the overall success of the attackers during this campaign brought about the downfall of Neville Chamberlain's government and forced King Haakon VII to flee to London.
One side during this military campaign joined it after realizing the unfeasibility of Operation Catherine. The launch of this campaign forced the cancellation of Operation Wilfred and Plan R 4, aimed at interrupting iron ore shipments. Planning for this campaign was accelerated after the destroyer HMS Cossack rescued 299 prisoners of war from an enemy supply ship during the Altmark Incident. The attacking side during this campaign faced setbacks when the cruiser Blucher was sunk by the Oscarsborg Fortress, and when several destroyers were sunk in the harbor at Narvik. The resistance organization Milorg was formed after this campaign, and it sabotaged attempts to produce heavy water. However, the overall success of the attackers during this campaign brought about the downfall of Neville Chamberlain's government and forced King Haakon VII to flee to London. For 10 points, identify this campaign at whose conclusion the Nazis appointed Vidkun Quisling as their puppet ruler of an occupied Scandinavian country.
One side during this military campaign joined it after realizing the unfeasibility of Operation Catherine.
Norwegian Campaign [accept equivalents, such as Nazi German invasion of Norway; accept Unternehmen Weserubung or Operation Weser-Exercise, which is the German codename for the campaign]