In 1392, the Ottoman Empire conquered the Second Bulgarian Empire. Bulgaria remained under Ottoman and Islamic rule for almost five centuries, but Christians in Bulgaria retained their culture and status, first as "dhimmis" and later as equals under the millet system, though until their liberation they were called giaour, meaning "infidel" as an offensive term. Muslim population in Bulgaria was a combination of indigenous converts to Islam, and Muslims originating outside the Balkans. According to scholarly consensus, conversion to Islam was voluntary as it offered Bulgarians religious and economic benefits. Missionary activities of the "dervish" orders resulted in mass conversions to Islam; though many converts retained Christian practices such as baptism, celebration of Christian holidays etc. Most of the urban areas became Muslim majority, whereas the rural areas remained overwhelmingly Christian.