The book, whose full title is Magnum crimen – pola vijeka klerikalizma u Hrvatskoj (The Great Crime – a half-century of clericalism in Croatia), was written by a professor and historian at Belgrade University, Viktor Novak (1889–1977).

As a result of this idea, in the Kingdom of Yugoslavia, the Roman Catholic Church identified Catholicism with Croatian nationhood,[10] which Novak argues turned most of its priesthood into ardent Ustashe supporters.

The second part, the last four chapters, covers the rise and fall of the 1941–45 Independent State of Croatia (NDH), and the active support of provided to it by the Catholic clergy.

Novak bases his gloomy picture of the NDH and the wartime not only on written documents which, despite strict police measures found their way to the occupied capital, but also on personal narratives by some of his fellow prisoners in the Banjica konclogor.

[9] Archbishop Aloysius Stepinac is portrayed in this book as an ardent Catholic crusader[18] who publicly endorsed the establishment of the NDH,[19] acknowledged the Ustashe as Croatian patriots,[20] defended it before the Roman Pope[21] and was responsible for the racist attitude and behaviour of his clergy.

Libellus accusations, both omitted in the original version under the pressure of Josip Broz Tito's OZNA chief Maks Baće.

The goal of the Sokol Society was to revive and enhance the national awareness and promote mental and physical health of the Czech people through sports and moral education.

[6] William Bundy gave a short survey of this book, the full text of which is: A Yugoslav historian's lengthy indictment of clericalism in Croatia over the past half-century.

The latter half of the book, covering the period of "independent" Croatian state of Ante Pavelić on the basis of a wealth of material from many sources, pays particular attention to the role of Archbishop Stepinac.

[30] Hubert Butler used Magnum Crimen as a starting reference for his research about the Croatian Society of St. Jerome in Rome and its support to the Ustashe during the Second World War and after.