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
Socialist Republic of Bosnia and Herzegovina three largest ethnic parties in the country won: the Bosniak Party of Democratic Action, the Serbian Democratic Party and the Croatian Democratic Union of Bosnia and Herzegovina. After the elections, they formed a coalition government. Parties divided the power along the ethnic lines so that the President of the Presidency of the Socialist Republic of Bosnia and Herzegovina was a Bosniak, president of the Parliament was a Bosnian Serb and the prime minister a Bosnian Croat. After Slovenia and Croatia declared independence from the Socialist Federal Republic of Yugoslavia in 1991, Bosnia and Herzegovina declared its sovereignty in October 1991