The dominant religion of Arabic-speaking north Africa, is Islam. It replaced Christianity in the 7th century and slowly spread west and south across the Sahara and into the equatorial zones. Today Islam includes about 41% of all Africans. | The dominant religion of Arabic-speaking north Africa, is Islam. It replaced Christianity in the 7th century and slowly spread west and south across the Sahara and into the equatorial zones. Today Islam includes about 41% of all Africans. |