The small middle class occupied the major population centers and almost everyone else were peasants engaged in subsistence agriculture. The largest ethnic group were Serbs followed by Croats and Slovenes, as three constitutive peoples of the Kingdom, while Montenegrins, Bosnian Muslims and Macedonians were not recognized as distinctive ethnic groups; further historical minority groups included Germans, Italians, Hungarians, Slovaks, Jews and Rusyns. Religion followed the same pattern with half the population following Orthodox Christianity, around 40% Roman Catholicism and most the rest Sunni Islam. Beside "Serbo-Croato-Slovene", the most widely spoken languages by number of speakers were Macedonian, Albanian, Italian, Hungarian, German, Slovak and Rusyn.