The four centuries of Ottoman rule also had a drastic impact on Bosnia's population make-up, which changed several times as a result of the empire's conquests, frequent wars with European powers, forced and economic migrations, and epidemics. A native Slavic-speaking Muslim community emerged and eventually became the largest of the ethno-religious groups due to lack of strong Christian church organizations and continuous rivalry between the Orthodox and Catholic churches, while the indigenous Bosnian Church disappeared altogether (ostensibly by conversion of its members to Islam). The Ottomans referred to them as ''kristianlar'' while the Orthodox and Catholics were called ''gebir'' or ''kafir'', meaning "unbeliever". The Bosnian Franciscans (and the Catholic population as a whole) were protected by official imperial decrees and in accordance and full extent of Ottoman laws, however in effect, these often merely affected arbitrary rule and behavior of powerful local elite.