Norway's participation in World War II began with the German invasion on 9 April 1940. The small Norwegian Navy and coastal fortresses sank several German warships. A handful of dauntless Norwegian pilots, hopelessly outnumbered and equipped with obsolete planes, nevertheless played an important part in slowing down the invasion. King Haakon VII and the Government escaped from Oslo and new headquarters and defence lines were set up. The Norwegian Armed Forces retreated, holding back the German forces unaided for three weeks before Allied help arrived. The combined Norwegian and Allied forces were, however, facing an enemy superior in manpower and equipment. In June, after another month of fighting in Northern Norway, active resistance on Norwegian soil came to an end and King Haakon and the Government went into exile in London.
By the time the resistance in Norway was over, the Norwegian Government-in-exile already had plans for reorganization of the Royal Norwegian Air Force. Plans for a training centre in France were abandoned with the fall of France. Instead, negotiations were begun with Canadian authorities resulting in the establishment of a main training centre in Toronto: "Little Norway". By August 1940, the site was chosen, and by November the camp opened.
Throughout the war, thousands of Norwegians escaped to join the Norwegian Forces in Great Britain. Most escaped through Sweden, or by way of the North Sea, some around the world via Russia, India, Africa and South America. Hundreds of them continued to Camp Little Norway to train to become pilots and aircrews before returning to the battlefields of Europe.
The first Norwegian unit went overseas to Iceland in April 1941. The first all-Norwegian fighter squadron with complete air and ground crew arrived in England in June 1941. A steady stream of airmen received their training at Little Norway, and returned to Europe to fight with distinction alongside Allied forces throughout the war.
Training was initially conducted using combat planes, some 20 million dollars worth, purchased from the United States before the war. They did not reach Norway in time to be used in the first months of the war. Instead, they were delivered to Little Norway. They comprised Fairchild PT-19 elementary trainers, Curtiss fighters, Douglas attack bombers and Northrop patrol seaplanes. They were later joined by Harvard trainers purchased with some of the 400,000 dollars received under the "Wings for Norway" fundraising campaign which received contributions from various Nordic associations, including some 100,000 dollars from Swedish-Americans, Norwegian expatriates, Canadians and Americans.
In 1942 a second training centre was established at Muskoka Airport, 120 miles north of Toronto. Once the Royal Canadian Air Force purchased the Toronto training centre, "Little Norway" was transferred to Muskoka, although the original aerodrome was still at the disposal of the Royal Norwegian Air Force.