FOUNDED: 632 C.E.
RELIGION AS A PERCENTAGE OF WORLD POPULATION: 2.2 percent

Overview

One of the two major branches of Islam, Shiism represents about 15 percent of the worldwide Muslim population. The initial split among Muslims occurred in Medina (western present-day Saudi Arabia) in 632 C.E. over the question of who would succeed the prophet Muhammad, but it took several decades before the division between the two branches, Shiism and Sunnism, became official. According to Shiites, the spiritual and temporal authority in the Muslim community rightfully belonged to Ali, the Prophet's cousin and son-in-law, and a succession of his descendants, known as the imams.

While Shiites live all over the world, they are most concentrated in Iran, where Shia Islam is the state religion. The majority of Iraq's population is also made up of Shiites. Other considerable Shiite communities live in Lebanon, Syria, the Gulf States, Saudi Arabia, East Africa...