[1] While working at the University of Zagreb, Novak, an ethnic Croat, was frequently attacked by Croatian nationalists for his balanced approach to the history of South Slavs and for his pan-Slavic Yugoslavist persuasion.
Viktor Novak dedicated many years to the extensive research of clericalism and extreme nationalism among Roman Catholic Croats in Croatia, Slavonia and Dalmatia.
[5] Novak would write: The future generations, freed of atavistic woes, with the aid of conscious national education, can bear in their hearts one great and holy idea, which will safeguard the people from external and internal enemies.
The Vatican Curia placed Magnum Crimen on their list of banned books Index librorum prohibitorum and named Viktor Novak "an enemy of Catholic Church".
As an ardent Yugoslav patriot and anti-fascist activist, Viktor Novak was during the Second World War arrested and spent some time in the Nazi detention camp at Banjica, near Belgrade.