His name is now a term that means traitor. That’s because after two decades of working for the Norwegian government in various roles, he collaborated with Hitler and the Nazi party, welcomed the German occupation of his country.
Research:

SYMHC Classics: Sarah Bradlee Fulton
32:28

Behind the Scenes Minis: Stairs and Trains
29:25

Elizabeth Blackwell's Curious Herbal
34:51