1. Introduction

Shia Islam is the second-largest branch of Islam, representing a tradition deeply rooted in the concept of divine leadership and spiritual succession. It is based on the conviction that the Islamic prophet Muhammad explicitly designated his cousin and son-in-law, Ali ibn Abi Talib, as his rightful political and spiritual successor. [1]

While Sunni Muslims accept the historical succession of the four “Rightly Guided” caliphs, Shia Muslims maintain that Ali alone was divinely appointed to lead the Muslim community (the Ummah). This belief in the Imamate—a line of infallible, divinely guided leaders from the family of the Prophet (ahl al-bayt)—is the cornerstone of Shia identity and theology. [1] [2]

Shia Muslims constitute an estimated 10–13% [2] of the world’s Muslim population, numbering approximately 200–260 million faithful followers as of 2026. The three principal Shia branches are Twelverism, Isma’ilism, and Zaydism. Shia Muslims form a majority in Iran, Iraq, and Azerbaijan, and comprise nearly half of the citizen population of Bahrain. [3] Substantial Shia communities also exist in Lebanon, Kuwait, Turkey, Yemen, Saudi Arabia, Afghanistan, and the Indian subcontinent. Iran remains the only country in the world where Shia Islam officially serves as the foundation of both its legal framework and system of governance. [4]

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2. Terminology

The word Shia (or Shīʿa; /ʃiːə/; Arabic: شيعي; pl. shīʿiyyūn) is derived from shīʿatu ʿAlī (شيعة علي, ‘followers of Ali’). [5] [6] [7] In Arabic, “Shīʿa” means followers and supporters; the term derives from al-shiyāʿ and al-mushāyaʿa, which convey the meanings of following, supporting, and obedience. Shia Islam is also referred to in English as Shiism (or Shīʿism) (/ˈʃiːɪz(ə)m/), and Shia Muslims as Shiites (or Shīʿites) (/ˈʃiːaɪt/). [8]

The term Shia was first used during Muhammad’s lifetime. [9] At present, the word refers to Muslims who believe that the leadership of the Muslim community after Muhammad belongs to ʿAlī ibn Abī Ṭālib, Muhammad’s cousin and son-in-law, and his successors. [10]

Nawbakhti states that the term Shia refers to a group of Muslims who, at the time of Muhammad and after him, regarded ʿAlī as the Imam and caliph. [10] [11] Al-Shahrastani explains that the term Shia refers to those who believe that ʿAlī was designated as the heir, Imam, and caliph by Muhammad, [10] [12] and that ʿAlī’s authority is maintained through his descendants. [10] [13] For the adherents of Shia Islam, this conviction is implicit in the Quran and the history of Islam. Shia Muslim scholars emphasize that the notion of authority is linked to the family of the Abrahamic prophets, as the Quranic verses 3:33 and 3:34 illustrate: “Indeed, Allah chose Adam, Noah, the family of Abraham, and the family of ‘Imrân above all people. They are descendants of one another. And Allah is All-Hearing, All-Knowing.” [14]

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3. Historical Foundations

The original Shia identity referred to the followers of Imam ʿAlī, [15] and Shia theology was formulated after the hijra (7th century CE). [16] The first Shia governments and societies were established by the end of the 9th century. The 10th century has been referred to by the scholar of Islamic studies Louis Massignon as “the Shiite Ismaili century in the history of Islam”. [17]

Origins

The Shia, originally known as the “partisans” of ʿAlī ibn Abī Ṭālib, Muhammad’s cousin and Fatima’s husband, first emerged as a distinct movement composed of those fiercely loyal to him during the First Fitna (656–661). Shia doctrine is founded on the understanding that ʿAlī was uniquely designated to lead the Muslim community after Muhammad’s death in 632. While the origins of Shia Islam remain a subject of scholarly debate, many Western historians have attempted to characterize early Shia Islam merely as a political faction rather than a religious movement, [18] [19] while others recognize this framework as an anachronistic imposition of the Western separation of religion and politics. [20]

Shia Muslims point to Muhammad’s explicit designation of ʿAlī as his successor during a major sermon at Ghadir Khumm, in which he declared: “Anyone who has me as his mawla, has ʿAlī as his mawla“. [21] [10] [22] [23] [24] Many versions of the sermon include the invocation: “O God, befriend the friend of ʿAlī and be the enemy of his enemy”. [25] The interpretation of this prominent proclamation is central to the Sunni–Shia divide: while Sunni scholars tend to interpret it as a general affirmation of ʿAlī’s merit, Shia Muslims maintain it to be a clear and unambiguous designation of ʿAlī as Muhammad’s appointed successor. [10] [26] [27] [28] Shia sources further record that those present at Ghadir Khumm immediately congratulated ʿAlī, acclaiming him as Amir al-Mu’minin (“commander of the believers”). [25]

When Muhammad died in 632 CE, ʿAlī and Muhammad’s closest relatives remained occupied with the solemn duty of his funeral arrangements. While they were preparing his body, Abū Bakr, ʿUmar ibn al-Khaṭṭāb, and Abu Ubaidah ibn al Jarrah convened a separate meeting with the leaders of Medina at Saqifa and secured the election of Abū Bakr as the first of the rāshidūn caliphs. While Sunni Muslims maintain that this election was politically legitimate, the process had no clear basis or precedent set by Muhammad, and ʿAlī’s partisans viewed it as a direct violation of the Prophet’s designation at Ghadir Khumm. Abū Bakr served from 632 to 634, followed by ʿUmar (634–644) and ʿUthmān (644–656). [21]

Following the assassination of ʿUthmān in 656, the Muslims of Medina finally turned to ʿAlī as the fourth caliph, [29] and he established his capital in Kufa. [5] ʿAlī’s subsequent rule over the early Islamic empire (656–661) was marked by entrenched opposition from rival factions. [21] The resulting conflict, known as the First Fitna, became the first major civil war within the Muslim community, encompassing a series of revolts against ʿAlī by groups that had initially affirmed the legitimacy of his caliphate before ultimately turning against him. [29]

Hasan, Husayn, and Karbala

The conflict began with the Battle of the Camel in 656, in which ʿAlī’s forces successfully prevailed against the coalition of Aisha, Ṭalḥah, and al-Zubayr. At the Battle of Siffin in 657, ʿAlī’s campaign to subdue Muʿāwiyah, the governor of Damascus, was frustrated by a forced arbitration that proved structurally disadvantageous to ʿAlī. [21] He subsequently withdrew to Kufa, where he decisively defeated the Khārijīs — former supporters who had fractured his coalition — at the Battle of Nahrawan in 658. In 661, ʿAlī was assassinated by a Khārijī while in a vulnerable state of prostration during prayer (sujud) at the Great Mosque of Kufa. Following this, Muʿāwiyah consolidated power, seized the caliphate, and founded the Umayyad dynasty. [31] [30]

Upon the death of ʿAlī, his elder son Ḥasan assumed leadership of the Muslims of Kufa. After a series of skirmishes between the Kufa Muslims and the army of Muawiyah, Ḥasan ibn ʿAlī agreed to cede the caliphate to Muawiyah and maintain peace among Muslims upon certain conditions: the enforced public cursing of ʿAlī, including during prayers, should be abandoned; Muawiyah should not use tax money for his own private needs; there should be peace, and followers of Ḥasan should be given security and their rights; Muawiyah would never adopt the title of Amir al-Mu’minin (“commander of the believers”); and Muawiyah would not nominate any successor. [32] [33] Ḥasan then retired to Medina, where in 670 CE he was poisoned by his wife Ja’da bint al-Ash’ath, after being secretly contacted by Muawiyah, who wished to pass the caliphate to his own son Yazid and viewed Ḥasan as an obstacle. [34]

Ḥusayn ibn ʿAlī, ʿAlī’s younger son and brother to Ḥasan, initially resisted calls to lead the Muslims against Muawiyah and reclaim the caliphate. In 680, Muawiyah died and passed the caliphate to his son Yazid, thereby breaking the treaty with Ḥasan ibn ʿAlī. Yazid demanded that Husayn swear allegiance (bay’ah) to him. ʿAlī’s faction, having expected the caliphate to return to ʿAlī’s line upon Muawiyah’s death, viewed this as a betrayal of the peace treaty, and Ḥusayn refused this demand for allegiance. There was a groundswell of support in Kufa for Ḥusayn to return there and take his position as caliph and Imam, so Ḥusayn gathered his family and followers in Medina and set off for Kufa. [21]

Later History and Dynasties

The period following the Battle of Karbala saw the development of various Shia movements and dynasties. Notable among these were the Idrisids in North Africa, the Fatimids who established a powerful caliphate in Egypt, and later various dynasties in Persia and India that promoted Shia Islam. These dynasties played a crucial role in shaping the political and cultural landscape of the Islamic world, often fostering intellectual and artistic flourishing. [35] [36]

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4. Core Beliefs & Practices

Core Doctrines

Shia Islam shares fundamental beliefs with Sunni Islam, such as the belief in one God (Allah), the prophethood of Muhammad, and the Quran as the holy book. However, key differences lie in the concepts of leadership and religious authority. Shia Muslims believe in the Imamate, the spiritual and political leadership of the Muslim community by divinely appointed Imams from the ahl al-bayt. These Imams are considered infallible and possess esoteric knowledge of the Quran and Sunnah. [37] [38]

Other core doctrines include:

• Tawhid (Oneness of God): The absolute monotheism of God.
• Adl (Justice of God): God is just and wise in all His actions.
• Nubuwwah (Prophethood): Belief in God’s prophets, with Muhammad as the last and greatest.
• Imamah (Leadership): Belief in the divinely appointed Imams as successors to the Prophet.
• Ma’ad (Day of Judgment): Belief in the resurrection and accountability for one’s actions.

Religious Practices

Shia practices largely align with Sunni practices, including the five daily prayers (Salat), fasting during Ramadan (Sawm), charity (Zakat), and pilgrimage to Mecca (Hajj). However, there are some distinct practices and interpretations:

• Prayer: Shia Muslims often combine certain prayers and may use a small piece of clay (turbah) during prostration.
• Ashura: The commemoration of the martyrdom of Imam Husayn at Karbala is a central and deeply emotional event, often involving mourning rituals, processions, and passion plays.
• Arba’een: A pilgrimage to Karbala, Iraq, forty days after Ashura, drawing millions of Shia pilgrims.
• Tawassul (Intercession): Seeking intercession from the Imams and other holy figures.
• Mut’ah (Temporary Marriage): A permissible form of temporary marriage in Shia jurisprudence.

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5. Major Branches of Shia Islam

Throughout history, several branches of Shia Islam emerged, primarily differing in their recognition of the line of Imams. The three principal branches today are Twelverism, Isma’ilism, and Zaydism.

Twelver Shia (Ithna Ashari)

The largest branch, representing approximately 85% of all Shias. They believe in twelve divinely ordained Imams, the last of whom, Muhammad al-Mahdi, is believed to be in occultation and will return as the promised savior. [39]

Isma’ilism

Recognize Isma’il ibn Jafar as the seventh Imam. They emphasize the esoteric (inner) meanings of faith. The largest group today is the Nizari Isma’ilis, led by the Aga Khan. [40]

Zaydism (Fivers)

Predominant in Yemen, they recognize Zayd ibn Ali as the fifth Imam. They hold a more political view of the Imamate, believing that any descendant of Ali and Fatima who rises against injustice can be an Imam. [41]

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6. Global Demographics

Shia Muslims constitute an estimated 10–13% of the global Muslim population, numbering between 200 and 260 million people. They form the majority in several countries and significant minorities in many others.

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7. History of Persecution

Shia Muslims have faced long periods of marginalization and persecution throughout Islamic history, often viewed as a threat by various ruling dynasties. This history of suffering has deeply influenced Shia spirituality and the emphasis on justice and martyrdom. [180] [185]

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References

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