Shia Muslims make up between 10-15% of Muslims worldwide. They believe that the Prophet Mohammed designated his cousin and son-in-law Ali ibn Abi Talib as his successor – Shia is a contraction of Shiat Ali, meaning “followers of Ali”.
Sunni Muslims, who make up approximately 85% of Muslims worldwide, believe that the Prophet did not appoint a successor and that his companion Abu Bakr should have succeeded him. Sunni means “one who follows the Sunnah” (the body of traditional Islamic belief and practice based on the verbal record of the Prophet’s teachings).
Shia and Sunni Islam differ in doctrine and practice and Shia Islam touches the emotions more than Sunni Islam, emphasising self-denial and martyrdom. Shias suffer discrimination in some Sunni-majority countries, and Sunni extremists persecute Shia Muslims because they consider them heretics.
Shia Islam is the state religion of Iran, followed by at least 90% of the population. Shia Muslims are also in the majority in Iraq, Azerbaijan and Bahrain (where a Sunni royal family rules a majority Shia population). They constitute large percentages in Yemen, Lebanon and Kuwait, and there are significant Shia communities in many other countries, including Afghanistan, India, Kuwait, Lebanon, Pakistan, Qatar, Syria, Saudi Arabia, Turkey and the UAE.
In the Middle East as a whole, Shias constitute 39% of Muslims and 36% of the entire population. Saudi Arabia and Iran are the dominant Sunni and Shia powers in the Middle East and take opposing sides in regional conflicts.
In Yemen, for example, Iran-backed Shiite Houthi rebels are fighting forces loyal to the deposed Sunni-dominated government, which is backed by a Saudi-led coalition.
In Syria, which has a Sunni majority but a government dominated by President Bashar al-Assad’s Shiite Alawite sect, Iranian troops and other Shia fighters (including Hezbollah) supported the government in fighting the Sunni opposition.
(BBC/Human Rights Watch/National Geographic/Pew Research Centre)