It's likely you're thinking of Vidkun Quisling, a Norwegian politician who collaborated with the Nazi regime during World War II. He was executed for treason after the war.
It's important to note that the term "quisling" has become a synonym for "traitor" or "collaborator" due to his actions.
If you have any other information about the author you're looking for, please provide it, and I can try to help you further.