10 of History's Most Notorious Traitors

Vidkun Quisling
Surrounded by soldiers, a pale-faced Vidkun Quisling begins the legal battle for his life in a crowded court room in Oslo. He lost and was executed by firing squad for treason. © Hulton-Deutsch Collection/CORBIS

Vidkun Quisling was a Norwegian army officer who was in cahoots with the Germans during their occupation of his home country during World War II.

Quisling joined the Norwegian Army in 1911, where his duties included humanitarian work in Russia and for the League of Nations. He later became minister of defense and was known for taking a strict stance on striking workers. He resigned in 1933 to pursue the formation of a National Union Party, which was an anti-union organization with fascist leanings.

In 1940, Quisling made a power grab. After meeting with Adolf Hitler, whom he encouraged to conquer Norway, he waited for the German occupation to become complete -- and then appointed himself Norway's leader. His reign lasted only a week before he was demoted by German forces to "minister president." That unfortunately, didn't stop him from sentencing almost 1,000 Jewish people to concentration camps [source: Encyclopaedia Britannica].

At the end of World War II in 1945, Quisling was found guilty of treason and executed. His name would forever live in infamy, as "quisling" became a synonym for traitor or collaborator [source: Encyclopaedia Britannica].