Algeria
Islam is the predominant religion in Algeria, with its adherents, mostly Sunnis, accounting for 99% of the population according to a 2012 CIA World Factbook estimate, and 97.9% according to Pew Research in 2010. There are about 150,000 Ibadis in the M'zab Valley in the region of Ghardaia.
Religion in Algeria
Before the Arab incursions, most of the Berber inhabitants of the area's mountainous interior adopted traditional Berber mythology. Some had adopted Judaism, and in the coastal plains many had accepted Christianity under the Romans. St. Augustine of Hippo, one of the most important theologians in Roman Catholicism, was born in Thagaste (Souk Ahras) and taught in Hippo (Annaba). A wave of Arab incursions into the Maghreb in the latter half of the 7th century and the early 8th century introduced Islam to parts of the area.