Sunni and Shia Demographics

Sunni Muslims make up the largest group of Muslims in the world, 85-90% by some estimates. Often regarded as orthodox Muslims, “Sunni” originates from the early leaders of Islam who administered the sunna (straight path) that attempted to follow Muhammad’s life and teachings.

Shia Muslims comprise about 10-13% of Muslims worldwide, and most live in Iran and Iraq, where they are in a majority.  But they also have a majority in the tiny country of Bahrain.   India and Pakistan also have small numbers of Shia.

The Divide

The historic divide between the two groups occurred after the death of Muhammad in 632 over the question of who should be caliph (leader) of the Muslim community. Sunnis insist the leader could be any member of the Muslim community, and Muhammad’s trusted friend Abu Bakr was voted in as the first caliph (632-634).

Shia Muslims contend that the Muslim leader should be a blood relative of the prophet, and they supported Muhammad’s cousin Ali, who became the fourth caliph (656-661). However, the murder of Ali in 661 caused a permanent Sunni-Shi’ite split, that has often been characterized by violence and bloodshed.

Sunni Distinctives

Sunni Muslims are considered the orthodox party because their beliefs are based on the Qur’an and Hadith (which contains the sunna) while their practices include the pillars of Islam: declaration of faith (shahada), five daily prayers (salat), fasting (sawm) during the holy month of Ramadan, almsgiving (zakat), and the pilgrimage (hajj) to Mecca. Historically, Sunni Muslims were led by a caliph who was elected by consensus of the community.

Shia Distinctives

Shia Muslims also adhere to the Qur’an, though their Qur’an contains some additional verses that Sunnis do not recognize.  Also, they have extra hadiths (statements about Muhammad) that Sunnis do not have in their hadith tradition. The Shia declaration of faith (shahada) refers to Ali as commander of true believers and a friend of God, while the call to prayer from Shia mosques also references Ali, in addition to Muhammad. Shia Muslims perform the pilgrimage to Mecca, but they actually place more value on pilgrimages made to the holy sites of Karbala and Najaf (modern Iraq), where Ali’s sons are buried. Historically, Shia Muslims preferred the leader of the Muslim community to be a prayer leader (imam) more than a political one (caliph) and they believed that divine light (nur) was passed down through the imams. Shia Muslims themselves later splintered into several different groups.


Understanding the history of Sunnis and Shia will not only help to explain the war between a Sunni-led Iraqi government and a Shia regime in Iran, during most of the 1980s, but it will also shed light on the ongoing Sunni-Shi’ite conflicts within present-day Iraq. In short, it will help us make sense of these two groups within the world of Islam(s).