This chapter analyzes three national interpretations of medieval Bosnian history: Serbian, Croatian, and Bosniak. Using representative examples, it examines how these interpretations shaped the historiographical landscape, particularly in the context of South Slav national movements. Scholarly interest in Bosnian medieval history, which gained momentum after World War II, was often driven by nationalist rather than scientific motives. The chapter addresses controversial issues that have fueled historiographical debates, such as the national affiliation of medieval Bosnia, the identity of its key figures, and the religious character of the domestic and independent Bosnian Church which was considered heretical by both the Catholic and the Eastern Orthodox churches. This suggests that medieval Bosnian history was appropriated as part of broader projects of national awakening among Croats and Serbs, and the process of state-building in the Balkans, which led to ideological conflicts. By providing an overview of competing historiographical narratives, the chapter examines the impact of the changing political contexts in Southeastern Europe on these disputes and sheds light on the region’s complex ethnic, cultural, and religious dynamics.