Bosnia and Herzegovina is roughly 51 per cent Muslim, 31 per cent Serbian Orthodox and 15 per cent Roman Catholic, according to the 2013 census — the first taken since 1991 and the first since the war that killed around 100,000 people. Those three figures correspond almost exactly to the country's three constituent peoples: Bosniaks, Serbs and Croats. In Bosnia, religious affiliation and national identity are the same statistic collected twice.
Why a Census Became a Political Crisis
The 2013 count was conducted under pressure from the European Union, which wanted comparable statistics, and it was contested from the moment the questionnaires were printed. Political parties ran campaigns instructing people how to answer the ethnicity, religion and language questions, because the answers would determine claims about which group belonged where.
When the results were published in 2016, the authorities of Republika Srpska rejected them, disputing the methodology used to decide who counted as a resident. The underlying issue was that the census would document how thoroughly the war had sorted the population: areas that had been mixed in 1991 were overwhelmingly single-community by 2013.
The Map Is the Point
Bosnia is divided into two entities plus a self-governing district, and the boundary between them is the line where the fighting stopped. Republika Srpska, covering about 49 per cent of the territory, is overwhelmingly Serb and Orthodox. The Federation of Bosnia and Herzegovina, covering most of the rest, is Bosniak and Muslim with Croat Catholic majorities in western Herzegovina around Mostar and Široki Brijeg. Brčko in the north-east is administered separately.
Before the war, Bosnia's villages and towns were mixed in ways that took centuries to form. Prijedor, Zvornik, Foča and Srebrenica all had large Muslim populations; Sarajevo had substantial Serb and Croat communities. The redrawing of that map through expulsion and killing, and the destruction of religious buildings as part of it, is the single largest fact about religion in modern Bosnia.
How Bosnia Became a Muslim-Majority Country in Europe
The Ottomans conquered the Bosnian kingdom in 1463 and ruled for more than four centuries. Conversion to Islam happened gradually over roughly two hundred years, driven by tax advantages, access to office, urban migration and the weakness of existing church structures, and it produced the only large indigenous Muslim population in Europe outside Albania.
An older theory held that Bosnia converted en masse because of the medieval Bosnian Church, a body sometimes described as dualist or Bogomil heretics who supposedly preferred Islam to Catholic persecution. Most historians now regard that account as unreliable: the evidence for dualist doctrine is thin and largely comes from hostile Catholic sources, and the conversion pattern was slow and uneven rather than sudden. The myth persisted because it was politically useful to several different parties.
What did make Bosnian Islam distinctive was its institutional form. It is Hanafi in law, Ottoman in its educational tradition, and organised through the Islamic Community of Bosnia and Herzegovina under a Reis-ul-ulema, a structure created under Austro-Hungarian rule after 1878 that gave Bosnian Muslims their own hierarchy separate from Istanbul.
The Franciscans and a Sultan's Charter
Catholic survival in Bosnia rests largely on the Franciscans, who had been the main pastoral presence since the fourteenth century. In 1463, shortly after the conquest, Sultan Mehmed II issued the Ahdname of Milodraž, a charter granting the Bosnian Franciscans protection, freedom of movement and the right to keep their monasteries.
The document is preserved at the Franciscan monastery in Fojnica and is one of the earliest charters of religious tolerance in Europe. Whether the Ottomans honoured it consistently is another matter, but the Franciscan order retained a presence that diocesan clergy could not, and Bosnian Catholicism to this day has an unusually strong Franciscan character, including a long-running jurisdictional friction between the order and the bishops.
Four Buildings Within a Ten-Minute Walk
Sarajevo's old town contains the Gazi Husrev-beg Mosque, completed in 1531 and the largest Ottoman mosque in the country; the Serbian Orthodox Cathedral of the Nativity of the Theotokos, finished in 1868; the Catholic Sacred Heart Cathedral, consecrated in 1889; and the Ashkenazi synagogue of 1902, with the old Sephardic synagogue nearby.
The proximity produced the nickname Jerusalem of Europe, and it is genuine rather than promotional: these are working buildings in a dense city centre, and the call to prayer and the church bells overlap daily. The Gazi Husrev-beg complex also includes a madrasa founded in 1537 and a library whose manuscript collection survived the shelling of the 1990s because staff moved it repeatedly under fire.
The Haggadah That Was Rescued Twice
The Sarajevo Haggadah, an illuminated Hebrew manuscript produced in Barcelona around 1350, reached Bosnia with Sephardic Jews expelled from Spain in 1492 and was acquired by the National Museum in 1894. It is among the oldest surviving Sephardic Haggadahs.
During the Second World War it was hidden from the Nazis by the museum's chief librarian, Derviš Korkut, a Muslim, who is said to have smuggled it out under his coat and concealed it in a village mosque or with a family in the mountains. During the siege of Sarajevo it was moved again, into a bank vault, and displayed in 1995 to demonstrate that it had survived. Its custody history is now a national parable, retold whenever the country's shared past needs an example.
What the War Destroyed, and What Came Back
Religious buildings were deliberate targets between 1992 and 1995. More than a thousand mosques were damaged or destroyed, along with Catholic churches and, in smaller numbers, Orthodox ones. The destruction was systematic: removing the physical evidence that a community had lived somewhere was part of removing the community.
Two cases became emblematic. The Ferhadija Mosque in Banja Luka, built in 1579 and on the UNESCO tentative list, was dynamited in May 1993 and the rubble carted away to a landfill. The sixteenth-century Aladža Mosque in Foča was destroyed the previous year. Both have since been rebuilt using recovered original stone, Ferhadija reopening in 2016 — though the 2001 ceremony to lay its foundation stone was attacked by a mob, with buses burned and attendees injured.
In Mostar, the Old Bridge, an Ottoman work of 1566 that was not a religious building but functioned as the symbol of a mixed city, was shelled into the river in 1993 and rebuilt in 2004. The city remains divided in practice, with Catholic Croats predominantly on the west bank and Muslim Bosniaks on the east.
Srebrenica
In July 1995 Bosnian Serb forces overran the United Nations safe area of Srebrenica and killed more than 8,000 Bosniak men and boys, an act two international courts have found to constitute genocide. The victims were selected by their identity as Muslims; the killing was organised, and the bodies were moved between mass graves to conceal it.
The memorial and cemetery at Potocari, where remains identified by DNA analysis continue to be buried each 11 July, is now the most significant site of religious commemoration in the country. The annual burial is an Islamic funeral conducted at national scale, and denial of the genocide remains routine in Republika Srpska politics, which is why the ceremony functions as an assertion as much as a mourning.
Imported Islam and Local Resistance
The war brought foreign fighters from the Arab world, some of whom stayed, and post-war reconstruction brought Gulf funding. The King Fahd Mosque in Sarajevo, opened in 2000 and financed from Saudi Arabia, is the largest in the country and architecturally alien to the Ottoman tradition around it.
Salafi communities established themselves in a small number of villages, most notably Gornja Maoča, operating outside the authority of the Islamic Community. The Islamic Community responded firmly, asserting that all mosques and imams in the country fall under its jurisdiction and moving to close unauthorised congregations, which it calls para-jamaats. Bosnian Islamic leaders have consistently framed the issue as a matter of institutional authority and of defending a European Hanafi tradition rather than as a security question alone.
Medjugorje: Six Children and Millions of Pilgrims
In 1981, six young people in the Herzegovinian village of Medjugorje reported apparitions of the Virgin Mary. The reports continued, and the village became one of the most visited Catholic pilgrimage destinations in the world, receiving millions of visitors and supporting an economy of hotels, coaches and religious goods in a region with little else.
The church's position was cautious for decades. The local bishops were sceptical, the Franciscans who ran the parish supportive, and Rome withheld judgement while permitting organised pilgrimage from 2019. In 2024 the Vatican issued a nihil obstat permitting devotion at the site while explicitly declining to pronounce on whether the apparitions are supernatural — a formula that legitimises the pilgrimage without endorsing the visions.
Two Schools Under One Roof
The most consequential religious institution in Bosnia today may be the school system. Confessional religious instruction is taught in public schools, and in much of the Federation a practice known as two schools under one roof operates: Bosniak and Croat pupils share a building but follow separate curricula, often entering through different doors and attending at different times.
Courts have ruled the arrangement discriminatory, and it persists. Children grow up learning different versions of the country's history, in classes organised by the religion they were born into, in a state whose constitution was written as a peace treaty. Whether that produces another generation of separate communities is the open question of Bosnian public life. More on the country is in our Bosnia and Herzegovina country guide; the valleys that kept these communities apart are covered in the geography of the Balkan peninsula, with the remainder in ten facts about Bosnia.
