What Islamic Branch Contains the Most Followers?

Islam is traditionally divided into three or four branches, based on the divisions among the early followers of the prophet Muhammad, with the best-known and most numerous being the Sunni and Shiite branches. Each of these branches is further divided into sub-branches. According to the article "2010 World Muslim Population," there are 1.6 billion Muslims, or 24 percent of the total global population.

According to Wabash College, Sunnis make up 85 percent of the total Muslim population. Sunnis believe that the Qur'an and the Hadith -- which are collections of Islamic oral sayings -- are the sources of guidance, and where these do not explain fully the correct course, this must be determined through consensus, or "ijma," and analogy, or "qiyas." Sunnism can be divided into four subgroups: "Hanafi," which is based on rationalism and is most popular in the Eastern Muslim world -- India, Pakistan, Central Asia as well as Iraq; Hanbali is predominant is Saudi Arabia, and is based upon the use of the Qur'an and the Hadith as the exclusive source of guidance; Maliki Sunnism is found in North Africa, as well as in parts of the Persian Gulf, and places the value of consensus over analogy in determining the correct path; and Shafi'i, which is most common in Indonesia, and holds that the Hadith is predominant, and that reason is not a religious construct. Of these groups, the Hanafi group is the most numerous, and has further split into two movements: the Deobandi and the Barelvi, which originated in the Indian subcontinent.

The Shi'ite branch of Islam split from the Sunnis over a dispute about the successors of Muhammad. The Shi'ite branch followed Muhammad's cousin, Ali, and regarded him as the first legitimate imam, or leader of the Islamic community. Shi'ites represent between 10 and 13 percent of the total Muslim population, notes The Pew Forum on Religion & Public Life, with the largest populations being in Iran, India, Pakistan and Iraq. Shi'ites believe in a more allegorical interpretation of the Qur'an, although they also believe in the infallibility of the seven imams who followed Ali.

The Kharijites were an early branch of Islam who rebelled against the rule of Ali, assassinating him in the process. Their outlook was essentially political, as they believed that any true Muslim could become the ruler of the faith -- although they reserved the right to rebel if he was not successful. The Kharijites, although one of the three early branches of Islam, do not exist today.

Sufism is often regarded not as a branch separate to Sunnism, Shi'ism and Kharijism, but simply as a different way of thinking about the faith. It split gradually as Islam became more powerful in the Arabian Peninsula. The word "Sufi" refers to the woolen clothes that early followers used to wear to symbolize their material poverty. Sufis are mystics, and have beliefs and practices that are based more on spiritual rather than material concerns. The numbers of Sufis are small, although The Pew Forum on Religion & Public Life notes that "There are no reliable figures on the proportion of Muslims worldwide who follow Sufi practices." According to the BBC, however, their influence is greater than their number.