Islam

In the mold of great Hebrew prophets, Muhammad combined both political and religious authority as the leader of the early Islamic community (umma). On his death in 632 the Prophet left no clear message as to how leadership of the Muslim community should devolve after him. Initially, therefore, divisions among Muslims were prompted by disputes over succession to the leadership of the community, rather than by doctrinal differences. The first five successors to the Prophet were, in fact, elevated in different ways to leadership of the community, reflecting the ambiguity among early Muslims about the Prophet's intentions regarding succession.

The majority position, which eventually appropriated the appellation Sunni to describe itself, held that in the absence of a clear message detailing an alternative arrangement, the Prophet intended for the Muslim community to proceed in selecting its leaders according to ancient Arab tribal custom. Traditionally, tribal leaders were selected from a relatively small pool of respected senior figures within the tribe. Once consensus on a new leader was achieved through deliberations of the tribal council, the choice of a new leader was confirmed by the public offering of an oath of allegiance, known as the bay'a, to the new leader by senior clan leaders within the tribe.

The earliest accounts suggest that following the Prophet's death, the early Muslim community in Medina was initially thrown into confusion even about whether or not the Prophet intended the Muslim community to remain unified under a single leader, combining both political and religious authority, or whether each tribe was expected to revert to selecting its own tribal chief. The matter was temporarily, though not decisively, resolved when 'Umar ibn al-Khattab, a highly respected figure among the Prophet's inner circle, offered the public bay'a to Abu Bakr, the Prophet's oldest and closest friend. This dramatic gesture convinced other leading figures to quickly follow suit in offering the bay'a to Abu Bakr. However, during his two-year reign Abu Bakr was engaged in re-extending authority over various tribes throughout Arabia that believed their submission to the Muslim state ended with Muhammad's death.

There was no doubt among the early Muslims that although the Prophet's successors would continue his function as political and religious leader of the umma, they would not continue his prophetic role. The Arabic term used among Sunnis to designate the successors of the Prophet is khalifat rasul allah (deputy of the Prophet of God), from which the English term caliph is derived. Sunnis recognize four legitimate caliphal successors to Muhammad: Abu Bakr (r. 632–634), 'Umar (r. 634–644), 'Uthman ibn 'Affan (r. 644–656), and 'Ali ibn Abi Talib (r. 656–661), who are collectively referred to among Sunnis as the "Rightly Guided Caliphs" (al-khulafa' al rashidun). Following the assassination of the last of these four caliphs in 661, the governor of Syria, Mu'awiya (r. 661–680), was successful in establishing the Umayyad dynasty, which ruled over the early Islamic empire for nearly a century. Although the Umayyads, like many dynasties that succeeded them, also claimed the title of caliph, subsequent Muslim historiography tended to refer to the Umayyad rulers as muluk (kings) to indicate that the political authority they exercised lacked the legitimacy of religious leadership over the umma, which the first four caliphs enjoyed.

Exact details of the succession disputes that established the three main divisions among Muslims are now clouded by centuries of partisan accounts, but the broad outlines are clear. During the first two decades after the Prophet's death, probably about the time of the accession of the third caliph, 'Uthman, in 644, a minority party among Muhammad's companions began to champion the cause of 'Ali ibn Abi Talib as the rightful successor to the Prophet. 'Ali was the first cousin and later son-in-law of Muhammad. He was also the son of Abu Talib, in whose house the Prophet had been raised after he was orphaned at age six. 'Ali clearly enjoyed a very close personal relationship to Muhammad, probably analogous to a devoted younger brother, and he is reported to have been the first male convert to Islam. Although 'Ali did not contest the elevation of the first three caliphs before him, the early histories make clear that 'Ali and his supporters resented his being passed over in favor of 'Uthman in 644. Devoted support to the cause of 'Ali survived his own assassination in 661 and was transferred to his two sons through the Prophet's daughter Fatima: al-Hasan (c. 625–669) and al-Husayn (c. 626–680).

The supporters of 'Ali and his heirs became known as shi'at 'Ali, "the party of 'Ali," from which the abbreviated shia (Shiite) comes. Over time the Shiites developed an elaborate doctrine rejecting the Sunni claim that the Prophet had left no clear message about succession after his death. Based on their own interpretation of a widely accepted statement made by the Prophet during his farewell pilgrimage to Mecca, the early Shiites asserted that Muhammad in fact left a very clear message that succession to the combined political and religious leadership of the Muslim community rightfully lay with 'Ali and his two sons through the Prophet's daughter Fatima. Shiites, therefore, rejected the first three caliphs, on whose memory they are known to invoke curses, in favor of 'Ali ibn Abi Talib and his descendents, whom they refer to as imams, rather than caliphs. In the early twenty-first century Shiites account for nearly 10 percent of the world's Muslims.

Kharijites, the smallest of the three major divisions among Muslims (currently less than 1 percent), also arose out of these early succession struggles. When 'Ali was elevated to the caliphate following the assassination of the third caliph, 'Uthman, in 656, the new caliph faced several challenges to his authority. The most serious opposition came from the governor of Syria, Mu'awiya, a cousin of the murdered third caliph, who suspected 'Ali of complicity in the death of his kinsman. Mu'awiya refused to give the bay'a (oath of allegiance) to 'Ali, which quickly led to battle between 'Ali's forces and the Syrian garrison. When stalemate was reached between the two sides, 'Ali reluctantly agreed to a call for arbitration in hopes of ending bloodshed between Muslims. Although the arbitration process ultimately proved futile, the very fact that 'Ali had accepted arbitration, rather than allow God to decide matters on the battlefield, prompted a group of 'Ali's own supporters to withdraw from among his ranks. Forced to make an example of these deserters, 'Ali's forces engaged and massacred them at the Nahrawan canal in Iraq in 658. Among Sunnis this group of deserters became known pejoratively as Khawarij, meaning "those who go out." In revenge for the massacre at the Nahrawan canal, 'Ali was himself assassinated by a Kharijite in 661. Like the Shiites and the Sunnis, the Kharijites eventually developed their own elaborate doctrine of the caliphate and their own legal schools. Essentially, the Kharijites held a radically egalitarian view of who was qualified to serve as caliph. They also came to hold an extreme view that any caliph who failed to apply or abide by the holy law of Islam forfeited both his office and his life—an idea that has inspired many modern Islamic political extremists.

The evolution and elaboration of each of these three major sectarian divisions among Muslims occurred slowly over time and did not spring wholly formed from these early disputes over succession. Each sect would also eventually generate numerous of their own subsects and divisions, which underscores the frequently unappreciated historical fact that the formation of Islam as a whole unfolded over centuries, not decades. Furthermore, the critical geographical location where the formation of Islam occurred between the mid-seventh and the mid-tenth centuries was not Arabia, but rather Syria and Iraq. The primitive form of Islam that came out of Arabia with the early Muslim conquests of the mid-seventh century, therefore, possessed very little of the sophisticated theological or legal superstructure recognized as so central to the tradition today. The fact that Islam came fully into formation in Iraq and Syria is significant because this area had long served as the frontier between the two great Mediterranean civilizations of late antiquity, Rome and Persia. As the new Islamic order began to take shape in this dynamic region between great empires, it drew important inspiration from both of the great civilizations that had previously dominated the Mediterranean world.

Unlike the earlier Christian experience, where slow conversion over nearly three centuries preceded the exercise of political power beginning in the reign of Constantine (r. 306–337), the early Islamic state came to dominate a vast empire in a remarkably short period. Within a century of the Prophet's death, Muslim armies had reached southern France in the west and northern India in the east. The rapidity of the early Muslim conquests, combined with the fact that Islam and the civilization that it inspired were still in formation, presented the Umayyad rulers of the first unified Muslim empire with enormous challenges. Faced with the task of administering a vast empire before the superstructure of Islamic law, institutions, political thought, and theology was yet in place, the Umayyads were compelled to make a variety of pragmatic administrative decisions that were effective but hardly uniform in character. Essentially, the Umayyads tended to confirm prevailing practice, whatever that might be, in the eclectic and far-flung empire they ruled from their capital in Damascus.

Unfortunately for the Umayyads, much of what eventually became accepted Sunni theory and practice of law, government, and administration was defined in opposition to whatever exigency-driven expediencies the Umayyads felt compelled to employ in ruling their empire. Not only does this circumstance explain the generally unfavorable evaluation of the Umayyads in subsequent Muslim historiography, but it also contributed greatly to the coalescence of opposition to the Umayyad dynasty, which resulted in their overthrow and replacement by the Abbasids in 750.

Under the Abbasids (750–1258), especially during the first three centuries of their rule, classical Islamic civilization reached fruition. Their new capital of Baghdad was by all accounts not only a fabulous city in its own right, but it was also a great magnet for artists, belletrists, craftsmen, and thinkers from throughout the Islamic world. It was thus during this golden age of early Abbasid rule that the distinctive and characteristic forms of classical Islamic thought and institutions took definitive shape.

By the mid-ninth century the political fragmentation of the universal empire was too advanced for the Abbasids to check. From this point forward, the political unity of the Islamic umma would remain an ideal for Muslims but not a practical reality as a host of local powers and regional empires asserted themselves. By this point, however, the basic outlines of classical Islamic thought and institutions were well enough established that they flourished even without the benefit of political unity that the universal empire had once afforded. This was a remarkably vibrant and highly cosmopolitan civilization of great cities, closely linked by shared religion and language, as well as by extensive crisscrossing trade networks and frequent artistic and intellectual exchange. Rival courts competed with each other in patronizing philosophers, scholars, theologians, jurists, physicians, craftsmen, writers, master builders, and poets, all of whose creativity and genius reflected positively on their benefactors. In this sense the political fragmentation of the universal empire from the mid-ninth century onward probably contributed greatly to the diverse and vibrant creativity of this period by ensuring multiple sources of patronage in all fields of learning and creative production. The economic vitality of Islamic civilization, with its vast and ever-expanding trade networks stretching from East Asia to the Atlantic and from sub-Saharan Africa to Central Asia, ensured an unparalleled level of wealth and further expanded the patronage base well beyond royal courts.