Having spent his entire professional career at the University of Oslo, he is especially known for his work on plagues, especially the Black Death.
In 1977 he published Fra rike til provins 1448-1536, volume five of the work Cappelens Norgeshistorie, on Norwegian history.
[1] He was promoted to associate professor, and from 1990 to 1992 he worked as manager of the Department of Archeology, Conservation and Historical Studies.
His main works having revolved mainly around Norway and the Nordic countries, Benedictow's book The Black Death 1346-1353: The Complete History, from 2004, is an extensive study of the impact of the Black Death, drawing on material from all over Europe.
[4] In addition to his academic work, Benedictow is known for prolific writing in print media, as well as giving lectures outside of the university.