Bosnia enters history as the last of the Southeast European Medieval states. Its original territory (the central part of today’s Bosnia and Herzegovina and the area at the upper Vrbas River) was initially an integral part of Serbia. The territory of Bosnia was afterwards incorporated into the First Bulgarian Empire and then annexed by the Principality of Zeta. Bosnia was captured by the Byzantines after the collapse of the First Bulgarian Empire but eventually the Hungarian influence became predominant. The territory of future Medieval Bosnia became a semi-independent Banate under Hungarian sovereignty by the middle of 12th century.
The reign of the first prominent Bosnian Ban, Kulin (1180-1204) was characterized by strengthening of central power as well as by the emergence and rise of the Bogomil (“Baboons”) movement resulting in foundation of an unique Bosnian Church which was neither Catholic nor Orthodox and has been considered heretical. The rise of the Bogomils in Bosnia disturbed the Popes who appealed to the Hungarian Kings. Ban Kulin rejected Bogomilism in the presence of the Pope’s legate in 1203 to avoid an eventual crusade but his act did not stop the spread of the Bogomil movement in Bosnia.
The period from Kulin’s death in 1204 until accession of Matej Ninoslav (1232-1250) was probably ruled by Ban Stephen who was most likely Kulin’s son. His reign was marked by further growth of Bogomilism and rise of power of local nobles. The spread of Bogomilism in Bosnia disturbed the Catholic Church which launched several campaigns to destroy the Bogomil movement. The pressure of the Catholic Church continued during the reign of Ban Matej Ninoslav who had to face a crusade led by Hungarian Herzog and son of Andrew II of Hungary, Coloman. Matej Ninoslav recognized the Hungarian rule and granted numerous lands in Bosnia to the Catholic Church in 1244 but the position of the Catholic Church in Bosnia did not improve. In 1247, he wrote to the Pope and claimed that he had always been a Catholic but the main purpose of his letter to the Pope was probably prevention of another military campaign against Bosnia. Matej Ninoslav died in 1250 but his successor was chosen by the Hungarians after four years of struggles in 1254.
Matej Ninoslav was succeeded by Prijezda I (1254-1287) who is considered the founder of the Kontroman Dynasty. The territory of Bosnia was at the time divided into several political units and the central power was greatly weakened. The crisis in Hungary at the end of the 13th century was taken advantage by the powerful lords in Croatia and Dalmatia. Paul I Subic Bribirski extended his domain to Bosnia and assumed the title Lord of the all Bosnia in 1299, while his brother Mladen I Subic was granted the title Bosnian Ban. However, a rebellion of the Bogomils broke out shortly afterwards and Mladen I was killed in a battle in 1304. Mladen I was succeeded by Paul’s son Mladen II who managed to retain his power in Bosnia until 1322 when he was decisively defeated in the Croatian civil war.
The defeat of Mladen II in the Croatian civil war enabled the restoration of the Kontroman Dynasty to the Bosnian throne. Stephen II Kotromanovic (1322-1353) managed to restore peace and order, and started the territorial expansion of Bosnia by conquering Usora and Soli on the north and capturing Zavrsje, lands from Cetina to Neretva and Zahumlje (medieval Serbian principality that was located in today’s Herzegovina and southern Dalmatia) reaching the Adriatic Sea. Bosnia reached its territorial peak under his successor Tvrtko I (1353-1391) who defeated Prince Nikola Altomanovic in alliance with the Serbian Prince Lazar and gained the Upper Drina area and the Lim area with Mileseva in 1373, and Konavle, Trebinje and Dracevica shortly afterwards. Tvrtko I crowned himself King of Serbs and Bosnia in Monastery of Mileseva in 1377 and took advantage of the political crisis in Hungary after death of Louis I (1382) to expand his territory westwards. The Hungarian Queen and Louis’s widow Elizabeth ceded him Kotor (1385) in return for his support against the rebellious Croatian nobility. However, Tvrtko I allied himself with the Croatian magnates, conquered Dalmatian cities except for Zadar and great part of Croatia, and assumed title King of Rascia, Bosnia, Dalmatia, Croatia and the Seaside.
Bosnia fell into decline after Trvtko’s death in 1391. The nobles refused to recognize his son as his successor and chosen his nephew Stjepan Dabisa (1391-1395). Struggles between the powerful noble families and Ottoman invasions after the Battle of Kosovo severely weakened the central power which was taken advantage by the Hungarian King Sigismund who took control over most of Bosnia in 1395. The central authority almost completely collapsed during the reign of Queen Jelena Gruba (1395-1398) and Bosnia wasde facto ruled by the three powerful noble families – Hrvatinici, Kosace and Pavlovici over the following four decades.
The Hungarian influence in Bosnia was replaced by Ottoman at the beginning of the 15th century. The Bosnian nobles appealed to the Ottomans for military assistance in their struggles against each other, while some of them even accepted the vassalage to the Ottoman Sultan. Stjepan Tomas (1443-1461) tried to repulse the Ottoman threat by converting to Catholicism and allying himself with Hungary, while his successor Stefan Tomasevic (1461-1463) turned for help to Pope Pius II. However, the help from the West never arrived and the Ottomans led by Mehmed II invaded and conquered Bosnia in 1463.