the presence of Glagolitic Catholic secular priests who celebrated the Slavic liturgy. The bishops did not dare to come to parts of their dioceses that fell under Turkish rule. That is why, in 1735, instead of the existing dioceses, the Holy See founded the Apostolic Vicariate in Ottoman Bosnia (Vicariatus Apostolicus Bosniae Othomanae). The Catholic church in Banja Luka was particularly hard hit during the War of the Holy League (1683-1699). In 1737 parish church in Banja Luka was burned and numerous believers migrated to the Habsburg possessions. After Bosnia Vilayet came under the Austro-Hungarian rule in 1878, Pope Leo XIII restored the vilayet's church hierarchy. In Ex hac augusta, his 5 July 1881 apostolic letter, Leo established a four-diocese ecclesiastical province in Bosnia and Herzegovina and abolished the previous apostolic vicariates. Sarajevo, formerly Vrhbosna, became the archdiocesan and metropolitan seat. Its suffragan dioceses became the new dioceses of Banja Luka and Mostar and the existing Diocese of Trebinje-Mrkan. After the renewal of the regular hierarchy, the Diocese was governed by the apostolic nuncio in Vienna, and from 1883 to 1884, by the Archbishop of Vrhbosna, Josip Stadler, who served as an apostolic administrator of the Diocese. At the time of its founding, the Diocese had some 36,000 believers. This number has accelerated rapidly with the arrival of the Austrian authorities. During the next decades, numerous Poles, Italians, Germans, Czechs and others moved in the area of the Diocese. During the Second World War and after the war, the Diocese was catastrophically harmed.. One third of all the parishes (13) have completely perished, in 10 of parishes a number of parishioners dropped significantly, and all the others were seriously injured. With a large number of killed believers, the diocese suffered severe loss of priests. During the war and after the war, at least 30 priests were killed. The Holy See started the process of beatification of 4 of them on 21 December 2014: Juraj Gospodnetić, Waldemar Maximilian Nestor, Antun Dujlović and Krešimir Barišić. Ordinaries Apostolic Administrators Bishops Auxiliary Bishops Demographics Diocese of Banja Luka has a population of 550,300. As of 2012, 35,428 (6.44% of the population) are Roman Catholics. Historical Roman Catholic population The historical Roman Catholic population is given in the following chart: Deaneries Churches Parish churches This is a list of Parish churches by deanery: Deanery of Banja Luka Church of the Visitation of the Blessed Virgin