In early April 1940, the political situation in Norway was rapidly changing due to the advancing threat of German military action in Europe. On the 9th of April, as German forces invaded Norway, Vidkun Quisling, who had previously led the National Unity Party, seized the moment to declare a coup. Announcing the formation of a new government, Quisling aimed to establish a regime that would embrace pro-Nazi policies. His proclamation was explicitly timed to coincide with the German military operations, signaling his alignment with Adolf Hitler's ambitions for Scandinavia.

This power grab was met with a mixture of confusion and anger within Norway. The Norwegian king and government were caught off guard, as Quisling's seize of power was seen as a betrayal to the nation. In cities like Oslo, the populace was profoundly impacted by the escalating violence of the German military as they swiftly occupied key locations. Quisling’s government was never fully recognized by the local populace, and many viewed him as a puppet of the Nazis, undermining his authority and legitimacy.

Quisling's collaborationist regime lasted until the liberation of Norway at the end of World War II. Following the war, Quisling became a notorious figure globally, synonymous with treachery and betrayal. His actions during the invasion and cooperation with Nazi Germany had lasting repercussions, leading to a complex legacy in Norwegian history regarding collaboration and resistance during the occupation. The modern use of the term 'Quisling' has become a descriptor for traitors in various contexts, further embedding this event into the larger tapestry of World War II narratives.