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
Croats of Bosnia and Herzegovina western Serbia and later part of the Kingdom of Croatia, which he accomplished by defeating various Croatian nobles and supporting Hungary. Thus, the Kingdom of Bosnia emerged, but part of present territory of Bosnia and Herzegovina remained in the Kingdom of Hungary. Regarding religion, Bosnia was closer to Croatia than the Orthodox lands to the east, and the Diocese of Bosnia is mentioned as Catholic in the 11th century, and later fell under the jurisdiction of the Archdiocese of Split and in the 12th Century under the jurisdiction of the Diocese of Dubrovnik. Another connection of Bosnia with Croatia is