Rochus Szmendrovich could hardly have found a territory better suited for missionary work than the Backa region, so uncommonly multi-religious and multi-ethnic in the mid-eighteenth century, even in European comparison. The plurality of Backa in ethnic and religious terms was mostly determined by demographic processes that took place after the Ottoman occupation. Devastated mediaeval villages were replaced by whole waves of new ones over the eighteenth century. In terms of religious and ethnic differences we rarely encounter sharp and clear boundaries. The definitive points in the composition were the Orthodox faith of the Serbian and the Roman Catholic affiliation of the South Slavic groups. The extent and frequency of conflict between the Catholic and the Orthodox denominations in the area of the Kalocsa archdiocese in the 1760s can be considered negligible when compared to the intense inter-religious conflict manifesting in other parts of Europe and certain power frictions related to Protestantism.