The Norwegian resistance to the occupation of Norway by Nazi Germany began after Operation Weserübung in 1940 and ended in 1945. It took several forms:
The Norwegian government of Prime Minister Johan Nygaardsvold, with the exception of foreign minister Halvdan Koht and minister of defense Birger Ljungberg, was largely caught by surprise when it became apparent in the early hours of 9 April 1940 that Nazi Germany had launched an invasion of Norway. Although some of the country's gold reserve had already been removed from Oslo, there were few contingency plans for such an invasion.
The Norwegian government was unprepared and unwilling to capitulate to the ultimatum timed to coincide with the arrival of German troops and delivered by Curt Bräuer, the German representative in Oslo. The German demand that Norway accept the "protection of the Reich" was rebuffed by Koht and the Norwegian government before dawn had broken on the morning of invasion. "Vi gir oss ikke frivillig, kampen er allerede i gang", replied Koht. "We will not submit voluntarily; the struggle is already underway."
Anticipating German efforts to capture the government, the entire Norwegian parliament (the Storting) the royal family, and cabinet hastily evacuated Oslo by train and car to Hamar and then on to Elverum, where an extraordinary session of parliament was called. In large part because of the presence of mind of the parliament's president C. J, Hambro, the Storting managed to pass an emergency measure (known as the Elverum Authorization) that gave full authority to the king and his cabinet until the Storting could convene again.
This gave King Haakon VII and the cabinet constitutional authority to reject the German emissary's ultimatum to accept the German invasion. Although there were several German attempts to capture or kill the King and the Norwegian government, they managed to evade these attempts and traveled through Norway's remote interior until leaving the country for London on the British heavy cruiser HMS Devonshire on 7 June.