The paper examines two ideologically radical Catholic groups, the group called Mladci Kristusa Kralja (Youth of Jesus the King, henceforth known as Mladci), and the group consisting of members of Akademski klub Straža (Straža Academic Club, henceforth known as Stražarji), which operated within the Slovene Catholic Action from the beginning of the 1930s until 1945. It examines their operations prior to, and during, the Second World War. In the period before the war, their relationship was generally hindered by the rivalry between the two groups and the question of prestige and prominence within the Slovene Catholic community. They were also influenced by the contrary characters of their leaders, Professor Ernest Tomec and Dr. Lambert Erlich. During the War the two groups took different roles in the ideological and armed conflict between the revolutionary and the counterrevolutionary camp; while the Mladci were generally more passive the Stražarji were considerably more active.