In 632, Muhammad died in Medina, in the hut of Aisha, his favorite wife. He had made no formal nomination of a successor, but he had appointed Abu Bakr to lead the prayers in the Mosque and, by implication, to become the next leader of Islam. However, the actual selection of Abu Bakr was made by a consultation of elders and Companions, establishing that the caliphate was not hereditary. Bakr’s original title was Khalifat Rasul Allah (“Successor of the Messenger of God”), later shortened to Khalifa, or caliph, and he and succeeding caliphs were deemed the rightful successors of Muhammad and true guides of Islam.
The issue of Muhammad’s successor led Islam to divide into what are now its two largest sects, Sunnis and Shi’ites (or Shia). Shi’ites were supporters of Ali ibn Abi Talib, Muhammad’s son-in-law (the word Shia means “partisans”). The Shi’ites contended that Ali should have been chosen to succeed Muhammad immediately, arguing that Muhammad had implied in various hadiths, accepted even by Sunni scholars, that Ali was to succeed him. They point additionally to the fact that Ali was the second person, after Khadija, to accept Muhammad’s teachings, that he was the prophet’s cousin and son-in-law (by marriage to Muhammad’s daughter Fatima), and that his sons, Hasan and Hussein, were the only grandchildren of the Prophet to survive into adulthood. And yet, in the communal negotiations following the death of the Prophet, Ali was passed over.
And so, Shi’ites disagree over the succession of the caliphs, whom they prefer to call Imams. This dispute more than any other has fueled the modern antagonism between Iraq, predominantly Sunni, and Iran, where Shi’ite beliefs have formed the official religion since the 16th century. To the Shi’ites, the Imam is a spiritual leader directly descended from Ali and a completely holy figure, infallible and without sin, who plays a more powerful spiritual role than the Sunni caliph. His decree, or fatwa, takes on the import of a divine command. Sunnis also honor Ali, but do not venerate their Imams as divine intercessors. (The Shi’ite use of the title Imam should not be confused with the more common imam, a local spiritual guide who, among other things, leads the regular prayers at a mosque, including the Friday sermon.)
Shia hierarchy includes the mullah (preacher), mujtahid (one allowed to render independent legal and theological opinions), Ayatollah (“Sign of God”), and Ayatollah al-Uzma, or Supreme Ayatollah — the rank held by the late Ruhollah Khomeini (1902-89). The last two are somewhat questionable 20th century titles accorded by a combination of popular sentiment and the approval of high-ranking Iranian theologians and legists. In fact, there may be more than one Ayatollah al-Uzma at a given time, but generally only one is considered the spiritual leader of Iran. Khomeini assumed this role following the Iranian Revolution of 1979, which overthrew the Shah and drew him from relative obscurity in France to Time’s “Man of the Year” within a span of 12 months. Islam has no central authority figure equivalent to the Pope or the Dalai Lama, but the Supreme Ayatollah comes close among the Shia.
A major difference in custom is the Shia practice of muta, or temporary marriage. An expedient created by the Shia to resolve the tension of momentary lust without resorting to either dishonor or sexual repression, muta may last only a few hours, but it legitimizes any offspring of the union. Sunnis disavow such a concept, even though their treatment of women is considerably less generous than that of the Shi’ites when it comes to family inheritance and participation in religious ritual.
The Shi’ites have divided into a number of sects, most prominently those known as the Twelvers and the Seveners, based on differing understandings of the succession of leaders following Muhammad’s death. The Seveners, or Ismailis, hold many doctrines influenced by Hinduism and Neoplatonism, and are still an influential force today, especially in India. Yet because they hold that Muhammad was not the last prophet, but was actually followed by a number of others, they are considered wildly heterodox not only by Sunnis but also by other Shi’ites. The Persian poet Omar Khayyam is thought to have been an Ismaili. Although he is most famous in the West for his Rubbaiyat, Omar was more notable in Persia as an astronomer and mathematician.