Saint Jerome, a Doctor of the Church born in Stridon (modern-day Šuica, Bosnia and Herzegovina), also wrote that St. Paul preached in Illyria.

Christians and bishops from the area of present-day Bosnia and Herzegovina settled around two metropolitan seats, Salona and Sirmium.

Several dioceses also were established in the south at Martari (present-day Konjic), Sarsenterum, Delminium, Baloie and Lausinium.

[2] With the collapse of the Western Roman Empire in 476 and with the ravaging and settling of Avar and Slavic tribes, this church organization was completely destroyed.

After the arrival of the Croats on the Adriatic coast in the early seventh century, Frankish and Byzantine rulers began baptizing them as far inland as the river Drina.

Christianization was also influenced by the proximity of old Roman cities in Dalmatia and spread from the Dalmatian coast towards the interior of the Duchy of Croatia.

For this reason, in 1233, Pope Gregory IX deposed Bishop Vladimir and appointed his successor John the German, who was also a Dominican friar.

Neither of these religious orders made an effort to educate the local secular clergy but instead fought over the influence in the country.

[8] The Franciscans gained a number of privileges, including the election of provincials, apostolic visitators, vicars and bishops.

The authorities issued them ahidnâmes, identity documents guaranteeing them freedom of movement (for priests), religious rituals, property and exemption from taxes for those receiving charity.

Mehmed the Conqueror issued two such documents to the Bosnian Franciscans – the first after the conquest of Srebrenica in 1462, and the second during the military campaign in the Kingdom of Bosnia in 1463.

Based on travel literature, it is believed that in the first half of the 16th century, the Catholic population still constituted a majority.

Serbs who came from the east were also identified as Catholic, and Turkish soldiers primarily constituted the Islamic population.

According to Apostolic visitor Peter Masarechi, in 1624 Catholics made up about a quarter of the population and Muslims the majority.

[10] The attempts of the Roman Curia to establish the regular church hierarchy in Bosnia and Herzegovina existed since the 13th century.

[13] The Franciscans opposed the efforts of local bishops to implement secular clergy in Bosnian parishes,[14] and even sought help from the Ottomans to push them out of the country.

[15] In 1612 and again in 1618, Rome sent Bartol Kašić, a Jesuit from Dubrovnik to report the situation in the lands under Ottoman rule in Southeast Europe.

Josip Stadler, professor of theology at University of Zagreb, was appointed archbishop of Vrhbosna, and the dioceses of Mostar and Banja Luka were entrusted to Franciscans Paškal Buconjić and Marijan Marković.

We must however point out that the number of such priests is more than negligible, and that the serious allegations which have been presented in the press and in the meetings against a large part of the Catholic clergy in Yugoslavia, have to be included within tendentious attempts to deceive the public aware of the lies, and take away the reputation of the Catholic Church ...[21] The earthquake that struck the Banja Luka area in October 1969 significantly damaged Banja Luka Cathedral, which had to be demolished.

[24] In August 1991, when war in Croatia had begun and was beginning in Bosnia and Herzegovina, Archbishop Puljić and Bishops Komarica and Žanić appealed to the authorities, religious communities and the international community to preserve Bosnia and Herzegovina as a state and prevent war.

Žanić believed that each ethnic group should have a separate administrative unit within the country, but Puljić and the leadership of the Franciscan Province of Bosnia Argentina insisted on a single state without divisions.

They opposed dividing Bosnia and Herzegovina into states because Catholic religious, sacred and cultural objects would remain largely outside the area granted to the Croats.

Pope John Paul II's 23 June 2003 visit to Banja Luka and Bosnia-Herzegovina for a beatification of Ivan Merz helped draw the attention of Catholics worldwide to the need to reconstruct the church in the country;[28] the destruction of churches and chapels was one of the most visible wounds of the 1992-95 war.

[28] In 2009 the remains of friar Maksimilijan Jurčić, killed by partisans on 28 January 1945, were discovered and buried in Široki Brijeg.

[29][30] Among those in attendance at his funeral was Ljubo Jurčić (the friar's nephew) and the Croatian consul-general in Mostar, Velimir Pleša.

[32] Medjugorje, a village in Herzegovina and a parish in the Diocese of Mostar-Duvno, has been the site of alleged apparitions of the Virgin Mary since 24 June 1981.

[33] The Holy See announced in March 2010 that it had established a commission under the auspices of the Congregation for the Doctrine of the Faith, headed by Cardinal Camillo Ruini, to evaluate the apparitions.

The village of Podmilačje, 10 kilometers from Jajce, was first mentioned in a 1461 document by King Stjepan Tomašević; at the time, the church had probably recently been built.