Hans Jacob Orning is a doctor of arts and professor of history at the University of Oslo. He has led several research projects and written a number of academic and popular science books on the Norwegian and European Middle Ages. He is a regular writer for the newspaper Klassekampen.
Svein Harald Gullbekk is a Ph.D. and professor of numismatics and history at the Museum of Cultural History, University of Oslo. He has led international research projects on religion and money and human sacrifice and written books on the history of medieval coinage and money.