The scientific study builds on the older paper already published, dealing with the Czech-Hungarian War in 1254 – 1256. The author analyses the conflict breaking out as a result of unpopular reign of Duke Stephan. This conflict represents one of the stages of the fight over the Babenberg heritage, one of the key conflicts in the 13th century Central Europe. War over the Babenberg heritage has not been processed in Slovak historiography very thoroughly before. Therefore, the author’s work is beneficial and pioneering in many aspects, providing a number of details and processing the wars over the Babenberg heritage in the context of Hungarian realia, in particular the relationship of the Hungarian king Belo IV with the Hungarian nobility and objectives of the Hungarian foreign politics. In addition, as a matter of course, he also deals in detail not only with the political but also with the military aspects of this topic. The study confirms the well-known fact that Belo IV as a sovereign was not very successful in his military actions. The author’s approach is also particularly important because the reign of Bela IV used to be processed in Slovakia mostly through the “social” topics, such as the foundation of towns, donation policy or counties. Paradoxically, only minor attention was paid to the political history. The author managed to collect a significant amount of primary sources, both of narrative and of diplomatic nature, as well as a collection of literature, mostly of foreign origin.