Shia–Sunni relations
The succession to Muhammad in 632 led the Muslims to be split into two camps, the Sunnis, who believed that the caliphs of the Islamic community should be chosen by a council, as in Saqifa, while a second group, the Shia, who believed that Muhammad had named his successor to be Ali ibn Abi Talib, his cousin and son-in-law.
Today there are differences in religious practice and jurisprudence, traditions, and customs between Shia and Sunni Muslims. Although all Muslim groups consider the Quran to be divine, Sunni and Shia have different opinions on interpretations of the Quran.
In recent years, the relations between the Shias and the Sunnis have been increasingly marked by conflict. The aftermath of the 1979 Iranian revolution, which reconfigured Iran into a theocratic Islamic republic governed by high-ranking Shia clerics, had far-reaching consequences across the Muslim world. The Iraq War further influenced regional power dynamics, solidifying Shias as the predominant force in Iraq. Iran's ascent as a regional power in the Middle East, along with shifts in politics and demographics in Lebanon favouring Shia, has heightened Sunni concerns about their Sunni–Arab hegemony. Recent years have witnessed the Iran–Saudi Arabia proxy conflict, as well as sectarian violence from Pakistan to Yemen, which became a major element of friction throughout the Middle East and South Asia. Tensions between communities have intensified during power struggles, such as the Shia led Bahraini uprising, the Iraqi Civil War, the 2013–2017 War in Iraq against ISIS, as well as the Sunni led Syrian Civil War. The self-styled Islamic State of Iraq and Syria launched a persecution of Shias.
While the exact numbers are subject to debate, the Shia comprise around 10% of the world's Muslims, and Sunnis 90%. Sunnis are a majority in most Muslim communities around the world. Shia make up the majority of the citizen population in Iran, Iraq and Azerbaijan, as well as being a minority in Bahrain, Lebanon, Saudi Arabia, Syria, Yemen, Nigeria, Afghanistan, India, Pakistan, Chad, Turkey, and Kuwait.
Demographics
s are the vast majority of Muslims in most Muslim communities in Central Asia. Within Shia Islam about 85% are Twelver, and within Twelver Shia, the overwhelming majority follow the Usuli school of jurisprudence. In Iran, an officially Shia country since 1501, around 90-95% of Muslims are Shia. 65–85% of Muslims in Azerbaijan are Shia. Shia, mostly of the Zaydi sect, form a large minority of the population in Yemen. About 10-20% of Turkey's population belong to the Alevi sect of Shi'i Islam. The Shia constitute around 25-30% of Kuwaiti citizens, 55% of the Muslim population in Bahrain, and 45-55% of Muslims in Lebanon, 10-15% of Saudi Arabia, 10-15% of Syria, and 10-20% of Pakistan. Around 10-20% of Afghanistan, less than 5% of the Muslims in Nigeria, and around 4-5% of population of Tajikistan are Shia. And less than 1% of Indonesia, Bangladesh and Egypt India has as many Shia as there are in Iraq.Scholar Vali Nasr has said that numbers and percentages of Sunni and Shia populations are not exact because "in much of the Middle East it is not convenient" to have exact numbers, "for ruling regimes in particular".
Differences in beliefs and practices
Successors of Muhammad
Mahdi
The Mahdi is the prophesied redeemer of Islam. While Shia and Sunnis differ on the nature of the Mahdi, many members of both groups believe that the Mahdi will appear at the end of the world to bring about a perfect and just Islamic society.In Shia Islam, "the Mahdi symbol has developed into a powerful and central religious idea." Twelvers believe the Mahdi will be Muhammad al-Mahdi, the twelfth Imam returned from the occultation, where he has been hidden by Allah since 874. Mainstream Sunnis' beliefs are somewhat different: The Mahdi forms an important component of Sunni eschatology, his appearance being considered the last of the minor signs of the Day of Judgment before its major signs. They believe the Mahdi will be a descendant of Muhammad named Muhammad and will revive the faith.
Hadith
The Shia accept some of the same hadiths of Muhammad used by Sunnis as part of the sunnah and the basis of divine law and religious practice. In addition, they consider the sayings of Ahl al-Bayt that are not attributed directly to Muhammad as hadiths. Shia do not accept many Sunni hadiths unless they are also recorded in Shia sources or the methodology of how they were recorded can be proven.Some Sunni-accepted hadiths—for example by Aisha or Abu Hurairah—are less favored by Shia.
Sufism
Shiism and Sufism are said to share a number of hallmarks: Belief in an inner meaning to the Quran, special status for some mortals, as well as veneration of Ali and Muhammad's family.Pillars of faith
The Five Pillars of Islam is the term given to the five duties incumbent on every Muslim and are held by both Sunni and Shia. These duties are Shahada, Salat, Zakāt, Sawm and Hajj. In addition, Shia theology has two concepts that define religion as a whole. These are Roots of Religion and Branches of Religion.Practices
Many distinctions can be made between Sunnis and Shiaīs through observation alone:Salat
When prostrating during Salah, Shia place their forehead onto a piece of naturally occurring material—most often a clay tablet or soil —instead of directly onto a prayer rug.There are five salat prayers at different times of the day, but unlike Sunni, some Shia combine two sets of the prayers, praying five times per day but with a very small break in between the prayer, instead of five prayers with some gap between them as required by Sunni schools of law.
Shia and the followers of the Sunni Maliki school hold their hands at their sides during prayer while Sunnis of other schools cross their arms and clasp their hands; it is commonly held by Sunni scholars that either is acceptable.
Mut'ah and Misyar
The Twelver branch of Shia Islam permits Nikah mut'ah—fixed-term temporary marriage. The practice is not allowed within the Sunni community, nor within the Ismaili Shia or the Zaidi Shia, who consider it planned and agreed fornication rather than marriage. These schools believe that mutah was permitted until Umar forbade it during his rule.Hijab and dress
Both Sunni and Shia women wear the hijab. Devout women of the Shia traditionally wear black as do some Sunni women in the Persian Gulf. Some Shia religious leaders also wear a black robe. Mainstream Shia and Sunni women wear the hijab differently. Some Sunni scholars emphasize covering of all body including the face in public whereas some scholars exclude the face from hijab. Shia believe that the hijab must cover around the perimeter of the face and up to the chin. Like Sunnis, some Shia women, such as those in Iran and Iraq, use their hand to hold the black chador in order to cover their faces when in public.Given names
Muslims are often named after famous early Muslims, so that given names of Shia are often derived from the names of Ahl al-Bayt. In particular, the names Fatema, Zaynab, Ali, Abbas, Hassan and Hussain are disproportionately common among Shia; while Umar, Uthman, Abu Bakr, Aisha are very common among Sunnis but very rare among Shia.Pilgrimages
The pilgrimage to Mecca, known as hajj, is one of the pillars of Islam for both Sunnis and Shi'ites, but Shia have many other holy sites they make pilgrimages to. Among them are Al-Baqi Cemetery near Medina, Najaf and Karbala, in Iraq, and Qom and Mashhad, in Iran.History
Early and pre-modern history
The origin of Shia Islam arose in response to the succession to Muhammad and whether Ali ibn Abi Talib or a more experienced member of the Quraysh tribe should succeed. The concept of Shi'ism further crystallized around events at the Battle of Karbala where Husayn ibn Ali, the son of Ali and grandson of Muhammad, was killed alongside many of his supporters. Thus a political split became a far more personal one, marked by blood feud, and a cause for further divergence.Even so, by the 13th to 14th century, Sunni and Shia practices remained highly intertwined, and figures today commonly associated with Shia Islam, such as Ali and Jafar al-Sadiq, played an influential role for Muslims.
Abbasid era
The Umayyads were overthrown in 750 by a new dynasty, the Abbasids. The first Abbasid caliph, As-Saffah, recruited Shia support in his campaign against the Umayyads by emphasising his blood relationship to Muhammad's household through descent from his uncle, 'Abbas ibn 'Abd al-Muttalib. The Shia also believe that he promised them that the caliphate, or at least religious authority, would be vested in the Shia imam. As-Saffah assumed both the temporal and religious mantle of caliph. He continued the Umayyad dynastic practice of succession, and his brother al-Mansur succeeded him in 754. Ja'far al-Sadiq, the sixth Shia imam, died during al-Mansur's reign, and there were claims that he was murdered on the orders of the caliph.Shia sources further claim that by the orders of the tenth Abbasid caliph, al-Mutawakkil, the tomb of the third imam, Hussein ibn Ali in Karbala, was completely demolished, and Shia were sometimes beheaded in groups, buried alive, or even placed alive within the walls of government buildings still under construction. The Shia believe that their community continued to live for the most part in hiding and followed their religious life secretly without external manifestations.
Iraq
Iraq holds a unique and foundational position in the history of Shia Islam. The roots of the Iraqi Shia community are deep, dating back to the seventh century. Ali ibn Abi Talib, moved the capital of the Rashidun Caliphate from Medina to Kufa in Iraq. Iraqi Shia identity further spread after the Battle of Karbala in 680, where Imam Husayn ibn Ali and his followers were martyred by the Umayyad army. The cities of Najaf, site of Ali's tomb, and Karbala, site of Husayn's shrine, became major pilgrimage sites and centers of Shia learning in Iraq. Six of the Twelve Imams have their tombs located in Iraq.In the early Islamic period, Iraq served as a primary hub for Shia scholarship and political activity. It was home to many renowned disciples of the Shia Imams and witnessed several uprisings against Umayyad rule, including those led by Sulayman ibn Surad and Mukhtar al-Thaqafi. While the Twelver sect eventually became dominant, other Shia sects like Zaydism among Kurds and Ismailism among the Musha'sha Arabs also had a historical presence in Iraq.
Medieval Iraq saw the rise of several native Shia dynasties that ruled parts of Iraq. In the 10th and 11th centuries, Hamdanid dynasty established an emirate in northern Iraq from their base in Mosul. They were succeeded by other Shia dynasties like the Uqaylids. In central Iraq, the Mazyadids, ruled an autonomous emirate from their capital, Hillah, from 961 to 1160, making it a major center for Shia scholarship.
Early-modern Iraq became a religious battleground between the neighboring Ottoman and Safavid Empires. For the Sunni Ottomans, who subscribed to the Hanafi school of thought, control over Iraq, and particularly Baghdad, the site of Abu Hanifa's shrine, was a major source of religious legitimacy. Conversely, for the Twelver Shia Safavids, sovereignty was fought for primarily due to the presence of the Al-Atabat Al-Aliyat, that is, the holy shrine cities of Najaf, Karbala, Kadhimiya, and Samarra. This rivalry resulted in centuries of conflict, plunging Iraq into a prolonged period of warfare in a religious struggle between the two major Islamic powers.
The Shia majority in Iraq was formed primarily through the mass conversion of Sunni Arab tribes in the 18th and 19th centuries. This process began after the collapse of the Safavid Iran in 1722 which recentered Shia learning back to Iraq, in Najaf and Karbala. The Wahhabi sack of Karbala in 1801 motivated the Shia scholars to convert tribes to secure their cities. A key trigger was the Ottoman policy of tribal settlement after 1831, which forced nomads into agriculture, disrupted their society, and created an identity crisis that made them receptive to conversion. This was aided by the construction of the Hindiyya canal, which drew tribes to settle in the fertile lands around the Shia holy cities, bringing them under the direct influence of Shia scholars.
The Ottoman-Persian rivalry split Iraq's society, as the state legally treated its Shia citizens as potential Persian subjects. Native Iraqi Arab and Kurdish Shias were often categorized as Persian subjects, a classification the Ottoman state used to justify discriminatory policies. These included religious fatwas condemning Shia as heretics and laws, such as those in 1822 and 1874, that prohibited marriage between Ottoman women and Shia men. This framework of viewing the Shia population through a lens of imperial security and sectarian difference continued to influence policies in the modern Iraqi state.