This master's thesis gives an insight into The Croatian Catholic movement from the time it was founded until the end of WW1. The Catholic Church tried to resist the new secularistic tendencies of the gouvernments by encouraging its clergy to get more involved with the people and also by encouraging laity, especially youth, to engage in a social and economic activities. Thought of the movement was initially against getting politicaly involved, but with dissolution of Austro-Hungarian Monarchy during WW1 the dominant thought started to shift more and more towards unifications of all South Slavs, at first inside of the Monarchy, but quickly towards a completely new political entity together with The South Slavs outside the Monarchy. This master's thesis tries to offer, on account of literature and then contemporary catholic journals, an overview of how the political ideas of The movement evolved from mostly Croatian nationalistic positions toward unitarian Yugoslavism. Catholics in a Croatian province of Dalmatia were the ones most involved with the people, spreading the ideas of The movement through the province more efficiently than the catholics in other parts of Croatian lands; also, part of Croatian Catholic clergy got more politically involved before WW1, that is before the official political party of The movement was started in 1919.