This thesis analyzes the writings of Croatian historians on the Bosnian Church, a subject which had long been the subject of various conflicting interpretation. This thesis focuses on the works of three prominent Croatian historians, Franjo Rački, Jaroslav Šidak and Franjo Šanjek, who have written on all aspects of the Bosnian Church and its history. The hypotheses of these three historians have greatly influenced the general historiography on the subject in the past 150 years. However, the thesis does not focus solely on these three major historians. It discusses the writings of other Croatian historians who have not written extensively but have still developed their own theories on the subject. These include the likes of Dominik Mandić, a church historian who focused on the theology of the Bosnian Church, and Ivo Pilar, who created a new theory of its origin based on the linguistic study of topographic terms. Finally, the thesis analyzes the overviews of medieval history of Croatia and Bosnia written by two influential Croatian medievalists – Nada Klaić and Tomislav Raukar to show their preferences. In conclusion, this thesis provides an overview of the historiographical debate on the Bosnian Church over the past 150 years highlighting specifically the major contribution of Croatian historians.