Croats of Bosnia and Herzegovina Dalmatian Croatia formed a united Croatian kingdom, which included Dalmatia and part of Bosnia and Herzegovina, Pannonia (eastern Slavonia and northeastern Bosnia), and Savia (western Slavonia). In 1102 Croatia entered into a union with the Kingdom of Hungary. After this, Bosnia, which was earlier part of the Kingdom of Croatia, started to disassociate with Croatia. At first, Bosnia became a separate principality under Ban Kulin who managed to solidify Bosnian autonomy at the expense of more powerful neighbours, but only in the 14th century did Bosnia become a formidable state. In the 14th century, King Tvrtko I conquered part of
Kostajnica, Bosnia and Herzegovina Kostajnica, Bosnia and Herzegovina Kostajnica (), is a town and municipality located in northern Republika Srpska, an entity of Bosnia and Herzegovina. It is situated in the part of the Кrajina region. As of 2013, it has a population of 5,977 inhabitants. The municipality was created from part of the pre-war municipality of Novi Grad. It is located across the Una from Hrvatska Kostajnica, Croatia. During the Bosnian War, it was renamed to "Srpska Kostajnica" (Српска Костајница). After that, name of the town was changed to "Kostajnica". According to the 2013 census results, the municipality has 5,977 inhabitants. In the