The Bosnian Church (crkva bosanska, ecclesia bosniensis) is historically thought to be an indigenous branch of the Bogomils that existed in Bosnia during the Middle Ages. Adherents of the church called themselves simply Krstjani ("Christians").

The church no longer exists and is thought to have disappeared completely by the Ottoman conquest of Bosnia and Herzegovina. The church's organization and beliefs are poorly understood, because few if any records were left by church members, and the church is mostly known from the writings of outside sources, primarily Roman Catholic ones.

HISTORY

Bosnia was on the boundary between the Roman Catholic and Eastern Orthodox churches. The Croats to the West and Hungarians to the North embraced Roman Catholicism, while the lands to the east and small southeastern parts of Herzegovina embraced Eastern Orthodoxy. The religious centre of the Bosnian Church was placed in Moštre, near Visoko, where the house of krstjani was founded.

During the later Middle Ages most of Bosnia was nominally Roman Catholic as well, but no accurate figures exist as to the numbers of adherents of the two churches. The Bosnian Church coexisted uneasily with Roman Catholicism for much of the later Middle Ages. Part of the resistance of the Bosnian Church was political; during the 14th century, the Roman Church placed Bosnia under a Hungarian bishop, and the schism may have been motivated by a desire for independence from Hungarian domination. Several Bosnian rulers were Krstjani, but some of them embraced Roman Catholicism for political reasons.

Outsiders accused the Bosnian Church of links to the Patarene heresy, and to the Bogomils, a Manichean sect centered in Bulgaria. The Inquisition reported about a dualist sect in Bosnia in the late 15th century and called them "Bosnian heretics", but this sect was according to some historians most likely not the same as the Bosnian Church.

The historian Franjo Rački wrote about this in 1869 based on Latin sources. It is thought today that the Krstjani, who were persecuted by both the Roman Catholic and Eastern Orthodox churches, accounted for the major part of Bosnia's converts to Islam. Some historians now believe that the Bosnian Church had largely disappeared before the Turkish conquest in 1463.

BOSNIAN CHURCH SCHOOLARSHIP

The phenomenon of Bosnian medieval Christians has been attracting scholars' attention for centuries, but it was not until the latter half of the 19th century that the most important monograph on the subject, "Bogomili i Patareni" (Bogomils and Patarens), 1870, by eminent Croatian historian Franjo Rački, had been published. Rački argued that the Bosnian Church was essentially Gnostic and Manichaean in nature.

The Beginning of the Gospel of Matthew, John, and a portrait of the evangelist Luke

This interpretation has been accepted, expanded and elaborated upon by a host of later historians, most prominent among them being Dominik Mandić, Sima Ćirković, Vladimir Ćorović, Miroslav Brandt and Franjo Šanjek.

However, a number of other historians (Leon Petrović, Jaroslav Šidak, Dragoljub Dragojlović, Dubravko Lovrenović, and Noel Malcolm) stressed theologically the impeccably orthodox character of Bosnian Christian writings and claimed that for the explanation of this phenomenon suffices the relative isolation of Bosnian Christianity, which retained many archaic traits predating the East-West Schism in the 1079.