Religions in the world of Fidem Pacis are divided among several major belief systems. The religion with the largest number of adherents is Islam, which is predominant in Europe, Ethiopia, the Indian Ocean region and parts of Leifria and Vanaheim. Islam is divided into two main branches - Greek and Hejazi - with the former being predominant in regions influenced by Roman culture, and the latter more common in areas of Arabic and Abyssinian influence.
Christianity was for a few centuries the dominant religion in Europe and the Middle East, but from the 7th century onwards it lost millions of believers to Islam. Today it is confined mainly to northern Europe and Vanaheim, but small populations of Christians are still to be found all over its former range.
Buddhism is the main religion of central and east Asia, the Pacific and western Vanaheim. Originating in India, it spread to China and East Asia and was later adopted by the Mongols. In much of central Asia it coexists with traditional shamanistic beliefs, producing a unique spiritual combination that is constantly finding new believers in Buddhist-minority countries.
Other world faiths include Zoroastrianism, the traditional religion of Iran; Hinduism, whose adherents are found mainly in India but also in scattered communities all over South Asia; Judaism, which has mostly been tolerated in Muslim-majority areas but has not been a powerful force in its own right for millennia; and many traditional religions of native peoples in Ethiopia and Leifria.