Shi'a Islam (Twelvers)
Shi'a Islam emerged among the followers of Ali ibn Abi Talib (d.661), the son-in-law of the prophet Muhammad, and favored the lineage of leadership in the growing Muslim community to remain in the hands of Muhammad's descendents. They believe that the twelfth leader (or Imam) went into concealment in 874 and will on day reappear, hence they are often termed Twelvers. They are the dominant form of islam in Iran, Iraq, Bahrain, and Azerbaijan. As the community developed, Shi'as looked to a slightly different collection of stories about Muhammad in the Hadith.