An ancient land in western Asia, Iran occupies a strategic crossroads: the Indian subcontinent and China lie to its east; Mesopotamia and the Mediterranean world to its west; Russia to the north; and the Persian Gulf and the Arabian Peninsula to its south. This geography has long made it a conduit for cultural exchange, commercial networks, and population movements. Today, Iran is also home to one of the largest Shia Muslim populations in the region, alongside countries such as Iraq, Syria, Lebanon, and Yemen.

As theologians such as Jon Armajani argue in Shia Islam and Politics: Iran, Iraq, and Lebanon (2020), this religious demography has enabled Iran both—to form alliances against external threats as well as mobilise its masses. A look at how Shiism took root in Iran and how Shia clerics have historically shaped and mobilised political action.

The Shi’is seceded from the great majority of the Islamic community in the seventh century (AD) due to a difference of opinion regarding the heirs of the Prophet Muhammad. After the death of the Prophet, three factions emerged, each claiming to be his rightful heir. “The debate was broadly focused on the issue of authority and legitimacy for that authority. The prophet, claimed the Sunni majority… won his authority through his character and achievements,” notes academic Ori Goldberg in Shi’i Theology in Iran: The Challenge of Religious Experience (2012). The prophet transformed a fragmented tribal society and turned it into a unified, monotheistic empire. Goldberg notes, “Therefore the Sunnis considered the prophet to be the man who brought border, prosperity and discipline.” When the prophet died (632 AD), the Sunni needed to know that their next leader could maintain the prophet’s achievements and perhaps add to them. They supported the selection of Abu Bakr, a close companion of the prophet, as the first caliph.

Shi’is, however, maintained a different view. They claimed that Ali ibn Abi Talib, the cousin and son-in-law of the prophet, was the heir apparent to Muhammad. “The Shi’is”, notes Goldberg, “claimed that the prophet’s legitimacy had to do with the fact that he developed an intimate relationship with God. All the members of the twelver chain (from Ali to the Imam Mahdi, the hidden Imam) carried a divine spark, a nass. The heir of the prophet should be someone related to him by blood, so as to keep the spark alive.” They wanted a leader who would serve as constant proof to them of God’s existence. This difference of opinion regarding authority, according to Goldberg, turned the Shi’is into a persecuted minority. In an interview with indianexpress.com, Goldberg adds, “Shi‘ism, since its inception around the 7th century, was for a long time a minority religion.” In its early centuries, he says, it functioned almost like a nomadic missionary movement, operating on the margins of power, while Sunni Islam remained the established creed.

Although there were Shiʿite kingdoms in Mesopotamia and communities in Iran, the historical heartland of Shiʿism was in Lebanon. “There, religious schools trained Shia clerics, some of whom travelled abroad to spread their teachings. In time, they encountered a confederation of warrior tribes on the Central Asian steppes known as the Safavid dynasty. These tribes were converted to Islam under Shia influence and gradually consolidated power.” By the early 16th century, the Safavids unified the territories of Iran under their rule.

The year 1501 was a turning point in Iran, when Shah Isma’il the Safavid established the first Shi’i state in Iran. The Safavids were warrior tribes from Central Asia. While they conquered and unified Iran, they lacked any sort of institutional legitimacy. They were also Shi’is of a militant, mystical school. Goldberg writes, “Since Shi’ism was never a dominant court religion, it prospered on the frontiers and peripheries of the Islamic world, eventually coming to power on a ticket of flexible mysticism rather than rigid, institutional doctrine.”

The Safavids began to import Shi’i religious scholars from abroad, mostly from the great scholarly centre in Lebanon, to provide religious legitimacy for their rule. They were quick to offer sound rewards to the native religious establishment in Iran, which was mostly Sunni. “The Safavids offered the Shi’i clerics (some of whom were Sunnis who had converted to Shi’ism) the support of a strong state. The clerics would receive state appointments and salaries, a chance to become an elite,” writes Goldberg. In return, they would profess their allegiance to the state and persuade their adherents to do the same.

According to Goldberg, the Iranian state had two leaderships: one religious, the other temporal. The religious leadership developed into a traditional elite with the support and funds of the state. Still, it never demanded the mandate to rule the country. The political community was never swallowed up into a religious social order. Religious scholars preferred to remain behind the scenes, occupying a pastoral role. “The Safavid model allowed for the joint, yet separate, development of the state and the religious establishment. The religious scholars relied on the state for institutional legitimacy, but also created religious venues for legitimization,” writes Goldberg.

The Safavid dual system functioned for just about 400 years. With the fall and disintegration of the Safavid state in 1722, and after some six decades of internal wars and political instability, the Qajar dynasty rose to power.

Western powers began to covet Iran’s resources and strategic location from the end of the eighteenth century onwards, and they played an active part in the machinations of the Qajar court. The religious establishment feared both for its elite status and for its role as the guardian of social morale and morality. In 1892, the clerics directly took on the monarchy when the leading source of emulation, Mirza Hassan Shirazi, published a religious decree forbidding the faithful to use tobacco products of any kind. This came about after the Qajar Shah granted a tobacco franchise to a British firm, allowing foreigners to take over tobacco production from the growing stage to the selling of tobacco products. An entire nation stopped smoking, and the Shah was forced to rescind his order. However, conflict ensued for the next three decades.

In Goldberg’s view, although Iran was long subject to British and Russian interference, it was never formally colonised. He argues that many Iranians interpret this resilience as closely tied to their religious identity. “In this understanding, Shiʿism is not merely a faith but an essential component of national identity.”

In 1925, Reza Shah Pahlavi was enthroned, establishing the Pahlavi dynasty. Goldberg notes, “Reza Shah had an agenda which viewed with disdain the Iranian-Shi’i system of multifocal, intertwined institutions and legitimacies. Reza Shah looked to the west, and wished to emulate the unitary structure of the western institutional state. He wished to change the balance of power in Iran, building a new state whose sole source of legitimacy and authority was the monarchy.” While this new identity did not reject Islam wholeheartedly, it was predominantly secular and saw its historical roots in Iran’s imperial, pre-Islamic past.

The Shah established a new, state-guided educational system which extolled the monarchy and was run by state-trained employees. Religious schools, the main form of popular education in Iran, were gradually replaced. The Shah also established a new legal system, adopting European codes and appointing Western-trained jurists as judges. By doing this, he undermined the livelihood of the religious scholars, while also removing their moral and public authority. Additionally, he wanted to take over as the nation’s spiritual guardian, not only to establish his status as absolute monarch. Mohammad Reza Shah positioned himself as an omniscient and omnipotent leader. For some religious leaders, this signalled an impending crisis in their traditionally stable relationship with the monarchy. “The ways in which the religious establishment regulated and influenced the creation of meaning in society were now being overtly threatened,” writes Goldberg.

Western-educated intellectuals denounced the Shah’s increasingly authoritarian rule, while traditionalists, including Shiʿa clerics, were alarmed by his state-driven Westernisation. By the late 1970s, the monarchy had become politically isolated and its social base eroded. This growing discontent set the stage for revolutionary upheaval, culminating in the Iranian Revolution of 1979, which overthrew the Pahlavi monarchy and established a Shia Islamic government in Iran.

As Goldberg explains in his interview, during the twentieth century, the Iranian state under Pahlavi Shahs pursued an aggressive programme of secularisation. The Shahs feared that if the population’s primary loyalty remained with Shia Islam, it might undermine allegiance to the monarchy.

However, these efforts ultimately failed to displace Shiʿism from Iranian public life. Shiʿa Islam remained central to popular identity, and its custodians—the clerics— retained authority. “Far from being isolated seminary scholars, Shia clerics were embedded throughout Iranian society, maintaining a direct relationship with the people. They were always political,” asserts Goldberg.

Since the 1979 Revolution, Iran’s leaders have woven Twelver Shia Islam into the state’s vision, using it both as a source of domestic legitimacy and a vehicle of regional expansion. Under the doctrine of velayat e faqih (guardianship of the Islamic jurist), leaders such as Ayatollah Ruhollah Khomeini held that Shia clerics would guide not just religious but also political life. Iran has also funded and backed the Hezbollah in Lebanon— a Shiite Muslim political and militant group that emerged in Lebanon following the Israeli invasion of the country in 1982.

The Iranian state has also leveraged religious and educational institutions, cultural centres, and media outlets to expand its ideological reach. It also preached the need to protect Shia shrines and emphasised the Shia struggle. Interestingly, the notionally shaped Shia Crescent region of West Asia also stands to represent Iranian influence and soft power. Including Lebanon, Syria, Iraq, Azerbaijan, and Yemen, it illustrates that Shi’ism is woven into the geography. Through this alignment, Iran hopes to expand its geopolitical footprint while countering rival Sunni powers like Saudi Arabia and external actors such as the United States and Israel.

Yet, Goldberg warns, “The widespread narrative that Sunnis and Shiʿa have been locked in perpetual religious warfare is misleading. While periods of tension and conflict have certainly occurred, for centuries, Sunni and Shia communities lived side by side across the Middle East. Even in the Gulf states, the two communities coexisted without embracing the notion that only one sect could survive.”

The notion of a 1,400-year-old Sunni–Shia war, Goldberg says, is largely a product of the past few decades, driven by regional rivalries and political agendas.