In 632 the Prophet Muhammad died in Medina, leaving a community of believers that already controlled much of the Arabian Peninsula but no agreed rule for choosing its next leader. Within a century, armies and governors acting in the name of that community ruled from the Atlantic coast of Spain to the edge of China. The civilization this course explores grew out of that astonishing expansion, and to understand its scholars, hospitals and libraries you first need to understand the state that paid for them.

The first caliphs

The leader of the community came to be called the caliph, from the Arabic khalifa, meaning successor or deputy. The first four caliphs, Abu Bakr, Umar, Uthman and Ali, ruled from 632 to 661 and are remembered by Sunni Muslims as the Rashidun, the "rightly guided." Their era saw the fastest conquests. Byzantine armies were defeated at the Yarmuk River in 636, Egypt fell in the early 640s, and the Sasanian Persian Empire, the great rival of Byzantium for centuries, collapsed entirely by 651. Both old empires had exhausted each other in a long war that ended in 628, and their weakness helps explain how fast they fell.

Disputes over succession began in these same years. Uthman was murdered in 656, Ali's caliphate was contested, and Ali himself was killed in 661. The quarrel over who should lead, and on what grounds, lies at the root of the later division between Sunni and Shia Islam.

The Umayyads

After Ali's death, Muawiya, the governor of Syria, founded the Umayyad dynasty, which ruled from Damascus from 661 to 750. Under the Umayyads, conquest pushed into Central Asia, across North Africa and, in 711, into the Iberian Peninsula. At first the empire was run by former Byzantine and Persian officials keeping records in Greek and Persian. The caliph Abd al-Malik (ruled 685 to 705) changed that: he made Arabic the language of government and issued coins with Arabic writing instead of images. Now anyone who wanted a career in administration, whatever their origin, had to master Arabic, and Arabic slowly became the shared language of science and letters across a vast area.

Conquerors and conquered

The conquests did not bring mass conversion. For generations Muslims were a ruling minority. Jews, Christians and Zoroastrians were generally classed as dhimmis, protected non-Muslims who kept their faith and communal law in return for paying a poll tax called the jizya and accepting a lower status. It allowed religious communities to survive and often flourish at a time when much of Christian Europe tolerated little religious dissent. It was also a hierarchy: dhimmis could face limits on dress, on building places of worship and on testimony in court, enforced more harshly in some times and places than others. Conversion grew slowly; one influential estimate, based on the spread of Muslim names, suggests that Muslims became a majority in Iran only in the ninth or tenth century, though such figures are rough.

Non-Arab converts, called mawali, often found that converting did not make them equal to Arab Muslims in pay or prestige. Their resentment, especially in the eastern province of Khurasan, fed the revolt that ended the Umayyads.

The Abbasid revolution

In 747 a movement marching under black banners rose in Khurasan, promising rule by the family of the Prophet. In 750 it overthrew the Umayyads and installed the Abbasid dynasty, descended from Muhammad's uncle al-Abbas. Almost the whole Umayyad family was killed, but one young prince, Abd al-Rahman, escaped to Spain, where his line would rule for nearly three centuries. The Abbasids shifted the empire's center of gravity east, toward Iraq and Iran, and drew heavily on Persian traditions of court life and administration.

The phrase "Islamic Golden Age" is a modern label, used loosely. It usually refers to roughly the mid-eighth to the mid-thirteenth century, from the Abbasid revolution to the Mongol sack of Baghdad, though some historians stretch it later. "Islamic" here describes a civilization, not only a religion: many of its leading scholars were Christians, Jews or Sabians, and many wrote in Persian as well as Arabic.

Worked example: reading a conquest story

Suppose you read two accounts of the fall of Egypt in the 640s. One, written centuries later by a Muslim chronicler, presents the conquest as a triumph of faith in which local Christians welcomed their new rulers. The other, by a Coptic bishop named John of Nikiu writing about fifty years after the events, describes killing, heavy taxes and fear. Neither is simply true or false. The first was written to celebrate a founding moment; the second by a churchman whose community suffered. Historians combine both with papyrus tax records, which show the new rulers keeping much of the old administration running. The fair conclusion is a mixed one. Conquest brought real violence and a new hierarchy, yet for many villagers daily life, language and church went on, and some Egyptian Christians did prefer the new rulers to Byzantine officials who had persecuted them as heretics. Asking who wrote each account, when, and why, is the first habit of a good reader of history.