In day-to-day religious practice and core beliefs, there is little difference between the two major Islamic denominations or sects: Sunni and Shi'a. Members of both sects believe in one God and in the Day of Judgment when every soul shall see the results of its deeds. Both believe in the same sacred text, the Qu'ran, which is the basis of their religion. Both follow similar practices with regard to prayer, worship, and charity. The similarities, then, outweigh the differences. It is history, then, not beliefs and practices, that divides them.
In the middle of the night, Muhammad often remained awake, bowing and kneeling in prayer to God. His eyes shed so many tears that his beard would become soaked. When asked what could cause such sadness to a man whose sins God had promised to forgive, Muhammad replied that he feared for the future of his community. Nations of the past had destroyed themselves through their mutual hatred and malice as well as through their pursuit of worldly riches. Unity was as essential to Islam's social structure as it was to Islam's theological doctrine. Despite his exhortations to his people to hold fast to brotherhood and unity, Muhammad's fears were realized only decades after his death.
The third leader or Caliph of Islam after Muhammad, Uthman bin Affan, was murdered by rebels within his own community. That murder heralded a political and religious conflict that has continued for over 13 centuries. Due to a series of misunderstandings, the fourth Caliph Ali, Muhammad's cousin and son-inlaw, found himself fighting a battle against none other than Muhammad's widow, Aishah. Ever a true Muslim, Ali refused to speak ill of his adversaries. They were not his enemies, he said; they were his brothers. When Aishah was captured, he pardoned her and treated her with full respect.
The first true sect to split off from the general Muslim community was the Kharijites movement. This group believed that if the Caliph did not live up to their standards, it was their right to violently oppose him, despite any amount of bloodshed. Although the Kharijites as a sect have not endured, they are often seen as precursors of modern militant terrorist groups such as al-Qaeda. Members of the Kharijite sect murdered Ali, leaving the path clear for Mu'awiyah's victory.
A minority of the Muslim community believes that Muhammad specifically designated Ali to be his successor. They are called the Shi'a 'Ali, or partisans of Ali. The majority of Muslims, known as the Sunni, believe that Muhammad never clearly designated a successor to lead the community after his death. They believe in the legitimacy of the first four caliphs, who were endorsed by most of the early Muslim community.
After Ali's death, the Shi'a rallied behind his two sons Hasan and Hussein, who were also Muhammad's grandsons. Hasan renounced politics to live a peaceful life in Medina, where he died in 669 C.E./41 A.H. Meanwhile, Mu'awiyah ruled the vast Muslim world as fifth Caliph, and would publicly slander Ali in religious ceremonies. This outraged Ali's devoted followers, who were concentrated around Kufah in Iraq. Mu'awiyah departed from the proto-democratic practices of his predecessors and appointed his son Yazid as his successor, establishing the first hereditary monarchy in Islamic history.
Shi'a accounts describe Yazid as Satan personified, a cruel, tyrannical despot, and the antithesis to the ideals of Islam. Instead of giving allegiance to such a man, the people of Kufah offered their support to Ali's remaining son Husayn, promising to back him in a bid for the caliphate. Yazid demanded that Husayn acknowledge him as caliph and swear allegiance to him, but the latter refused. Husayn set off for Kufah with his most devoted followers, including men, women, and children. Yazid's generals intercepted him in the arid plain of Karbala. Against the thousands of Umayyad soldiers, Husayn's small company stood no chance. Husayn and his warriors resisted and were slaughtered, and the women and children were marched off in chains.
Husayn's martyrdom is extremely important to Shi'a Muslims; it is comparable to the martyrdom of Jesus in Christianity and reminiscent of the sacrifice offered by Abraham and his son, thousands of years earlier. The tragedy happened on the 10th day of the lunar month of Muharram on the Islamic calendar, the same day when Moses led the Israelites out of bondage and when Jews fast on their Day of Atonement. Muslims call the day Ashura, and Muhammad used to fast that day in accordance with the earlier Jewish tradition. For Shi'a Muslims, it is the holiest day of the year. The people of Kufah, under pressure from Yazid's forces did not come to Husayn's aid in his hour of need, and thus the Shi'a as a whole failed their leader. Ashura is a day of collective guilt and mourning, and some people participate in rather gruesome self-punishing rituals that are frowned upon by Sunni Muslims.
The story of Husayn's martyrdom is both history and legend at once, and it is impossible to separate the two. It is said that Husayn left for Iraq before completing his pilgrimage in Mecca. When asked about his strange decision, he replied that he would instead perform the pilgrimage in the desert of Karbala, where he would sacrifice not the traditional animal but instead sacrifice himself, his family, and his friends. When surrounded by 30,000 enemy soldiers in the burning desert of Iraq, he reminded his followers that they could escape, as it was he who the enemy was after. All of them refused, and stood by Husayn until each was slain. Husayn made several offers of peace, but all were rejected by his foes. When he was preparing to fight, Husayn saw his infant son dying of thirst and pleaded with the enemies for water. He was answered with a poisoned arrow that pinned the child's neck to the father's arm. In a final prayer, Husayn declared his absolute surrender to God, and proceeded to battle the forces of Yazid until he was slain and his head fixed upon the tip of a lance.
Indeed, any attempt to weed out imaginative embellishments from certain historical fact would bypass the beauty, valor, and tragedy of the tale. The impossible odds, the certain failure, the heroic struggle against the forces of tyranny, and the ultimate martyrdom have provided guidance and strength for the Shi'a in the many eras when they have suffered oppression. A major legal difference between the Sunni and the Shi'a lies in the concept of the Imam in Shi'ism. Instead of Caliphs, the Shi'a revere a series of leaders called Imams, all of whom were members of Muhammad's family. The first Imam was Ali, who married Muhammad's daughter Fatimah. Their sons Hasan and Husayn were the second and third Imams, respectively. Ali, Fatimah, Hasan, and Husayn are referred to as the ahl-ul-bayt (people of Muhammad's house), and are sacred to the Shi'a. Only their descendants can become Imams. One of Husayn's sons survived the Karbala disaster to carry on the Imamate.
In Shi'ism, Muhammad and the Imams are believed to be infallible and sinless. Unlike the caliphs for the Sunni, the Imams were not only political leaders, but also religious and spiritual guides, believed to be divinely inspired. The teachings of the Imams constitute a source of law in Shi'ism-in addition to the Qur'an and the teachings of Muhammad.
Disagreement over Imams has led to several subdivisions within the Shi'a sect. The majority of Shi'a recognized Muhammad al-Baqir as the fifth Imam, but some followed Husayn's grandson Zayd instead and became known as the "fivers." Another minority disagreed about the seventh Imam, and became known as the Ismailis or "seveners." Several Ismaili chains of Imams have endured into the present day.
The majority of Shi'a Muslims are called "twelvers." The eleventh Imam, Hassan al Askari, died without an heir, causing a potential problem for his followers, since according to Shi'a belief there will never be an age without an Imam. Twelvers believe that his son, Mohammad al-Mahdi, the twelfth or "hidden" Imam who mysteriously disappeared as a child, will return near the end of time and lead his people to victory. The government of modern-day Iran is a twelver Shi'a theocracy.
The story behind the divide between Sunnis and Shi'as is, then, a story about leadership, and leaders' political authority, as well as religious and spiritual authority. This is not, then, a story unique to Islam. Rather, it is a story told in different ways in all the major world religions.