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
Bosnia and Herzegovina the Pannonian Plain stretching into neighboring Croatia and Serbia. The country has only of coastline, around the town of Neum in the Herzegovina-Neretva Canton. Although the city is surrounded by Croatian peninsulas, by international law, Bosnia and Herzegovina has a right of passage to the outer sea. Sarajevo is the capital and largest city. Other major cities are Banja Luka and Bihać in the northwest region known as Bosanska Krajina, Bijeljina and Tuzla in the northeast, Zenica in the central part of Bosnia and Mostar, the largest city in Herzegovina. There are seven major rivers in Bosnia and Herzegovina: Phytogeographically,