Quisling, Vidkun (1887-1945), Norwegian politician, whose collaboration with the Nazis during World War II made his name synonymous with traitor. Quisling aided Fridtjof Nansen on his humanitarian missions in the USSR and Armenia in 1922-1925 and later served in the Norwegian legation in Moscow. Returning to Norway, he entered politics, voicing strong anti-Communist sentiments. He served as minister of defense (1931-1933) in an Agrarian cabinet, but then bolted to found his own National Union, a Fascist party that received subsidies from Germany. At the time of the Nazi invasion of Norway in 1940, the German envoy tried unsuccessfully to have King Håkon accept Quisling as prime minister, and the National Union was subsequently declared the only legal party. The Germans finally installed Quisling as prime minister in 1942, and throughout the war he collaborated with the Nazis and tried to inject their principles and practices into Norwegian society. Largely responsible for the persecution of Norwegian Jews, he also introduced terrorist methods in dealing with those loyal to the king and the legal government in London. Arrested, tried, and sentenced by a Norwegian court after the war, Quisling was executed on October 24, 1945.