The Challenge of Islam

A new prophet

In the early 600s, Christianity seemed secure across the Mediterranean world and much of the Middle East. Then something happened that no one foresaw. In the trading town of Mecca in western Arabia, a merchant named Muhammad (c. 570–632) began to proclaim revelations that he said came from God through the angel Gabriel. They were later collected as the Qur'an.

His message was a fierce monotheism. There is no god but God (Allah in Arabic). Idols must be abandoned. A day of judgment is coming, and people must submit to God's will. "Islam" means "submission," and a Muslim is "one who submits." Muhammad saw himself as the last in a line of prophets that included Abraham, Moses and Jesus. The Qur'an honors Jesus (Isa) as a great prophet and Messiah, born of the virgin Mary. But it denies that he is the Son of God or that he died on the cross, and it rejects the Trinity as compromising God's oneness.

Arabia was not cut off from Christianity. Christians, including Miaphysites and members of the Church of the East, lived among Arab tribes and in the Yemen. Muhammad had contact with Christians and Jews, and the Qur'an shows knowledge of biblical stories, sometimes in forms found in apocryphal writings. Christians in the following centuries often regarded Islam as a Christian heresy rather than a new religion. John of Damascus included it in his list of heresies.

Facing opposition in Mecca, Muhammad moved in 622 to Medina, an event called the Hijra ("migration"). It marks year 1 of the Islamic calendar. There he built a community that was religious, political and military all at once. By his death in 632, most of Arabia had accepted Islam.

The great conquests

What happened next astonished the world. Under Muhammad's successors, the caliphs, Arab armies burst out of Arabia. Both great empires of the region, Byzantium and Persia, had exhausted themselves in a long war (602–628) that ended just before the Arabs arrived.

• Syria and Palestine: At the Yarmuk River in 636 the Arabs crushed the army of the Byzantine emperor Heraclius. In 638 Jerusalem surrendered. Its patriarch, Sophronius, negotiated terms with the caliph Umar ibn al-Khattab, who, according to tradition, refused to pray inside the Church of the Holy Sepulchre so that Muslims would not later claim it.
• Persia: The Sasanian Empire collapsed by 651, and Zoroastrianism declined.
• Egypt: Alexandria fell in 642. The church of Athanasius and Cyril was now under Muslim rule.
• North Africa: Carthage, the city of Tertullian and Cyprian, fell in 698. The Latin church of North Africa, once among the strongest in the world, eventually disappeared completely.
• Spain: In 711 Muslim forces crossed from Morocco and quickly conquered the Visigothic kingdom.
• Into France: A Muslim raiding army was defeated near Tours/Poitiers in 732 by the Frankish leader Charles Martel ("the Hammer"). Older histories treated this as the battle that saved Christian Europe. Modern historians see it as a defeat of a raid at the limit of Muslim expansion, but it boosted the Frankish dynasty that would produce Charlemagne.

Constantinople itself was besieged twice (674–678 and 717–718) but survived, defended by its massive walls and a secret weapon, "Greek fire," a burning liquid that could not be put out with water.

The Arab conquests, 632–750

Why so fast?

Historians point to several factors. The Byzantine and Persian empires were exhausted. The Arab armies were mobile, motivated and well led. And many local populations, especially the Miaphysite Christians of Egypt and Syria who had been persecuted by Constantinople (see Churches Beyond Chalcedon), did not fight hard for their Greek overlords. Some may even have welcomed a change. The new rulers generally did not force conversion. They were happy to rule and tax a non-Muslim majority.

Christians under Muslim rule

Under Islamic law, Jews and Christians, as "People of the Book" who had received earlier scriptures, were granted the status of Dhimmi, "protected people." They could:

• keep their churches and worship privately,
• run their own communities under their own law in family matters,
• work in trade, medicine and government administration.

But they also faced restrictions, which varied greatly from ruler to ruler:

• a special poll tax, the jizya;
• bans on building new churches, ringing bells loudly, or holding public processions;
• bans on converting Muslims, with death the penalty for a Muslim who converted to Christianity;
• sometimes distinctive clothing, and rules against riding horses or carrying weapons.

It was a second-class status, but often more tolerant than the treatment Christian states gave religious minorities at the time. Periods of peace alternated with waves of persecution. Under some rulers, such as the Fatimid caliph al-Hakim, who destroyed the Holy Sepulchre in 1009, Christians suffered severely.

Over centuries, Christian populations steadily declined through conversion. It brought tax relief, social advancement and acceptance. Intermarriage also played a part, since children of mixed marriages were raised Muslim. Egypt probably did not become majority-Muslim until around the 900s or later. In North Africa west of Egypt, Christianity died out entirely by about 1200. In Syria, Iraq and Egypt, substantial Christian minorities survived to the present.

Christians in the caliphate

Christians did not simply disappear into the background. Under the early caliphs they served as officials, doctors and scholars. John of Damascus (c. 675–749), whose family had served in the caliph's financial administration in Damascus, became a monk near Jerusalem and one of the greatest theologians of the Orthodox Church. He wrote a defense of icons from the safety of Muslim territory, out of reach of the Byzantine emperor (see Byzantium and the Icons).

In Baghdad, capital of the Abbasid caliphs from the 760s, Christians of the Church of the East and Syriac scholars led a great movement translating Greek philosophy, medicine, mathematics and astronomy into Arabic. One of them, Hunayn ibn Ishaq (809–873), translated Galen, Aristotle and Plato. Muslim philosophers like Avicenna and Averroes built on these translations. In the 1100s and 1200s the same works reached Christian Europe through Spain and Sicily, sparking the rise of scholasticism (see Cathedrals, Universities and Scholastics). The Church of the East's Catholicos Timothy I even held a famous respectful debate about Christianity with the caliph.

Spain: coexistence and conflict

In Muslim Spain, called al-Andalus, Christians (known as Mozarabs), Jews and Muslims lived side by side. Some modern writers have romanticized this as a golden age of tolerance (convivencia). Reality was more mixed. In the 850s in Córdoba, about fifty Christians, encouraged by a priest named Eulogius of Córdoba, deliberately insulted Islam in public and were executed. They were the "martyrs of Córdoba." Many local Christians thought them fanatics who endangered everyone.

From the north, small Christian kingdoms began a long reconquest (Reconquista), which ended only in 1492 with the fall of Granada.

A redrawn map

The rise of Islam permanently changed Christianity. Three of the five great ancient patriarchates, Alexandria, Antioch and Jerusalem, came under Muslim rule. Only Rome and Constantinople remained in Christian hands, which sharpened their rivalry. Christianity's center of gravity shifted north, to Europe. The confrontation between Christendom and the Islamic world would shape the next thousand years, through the Crusades, the fall of Constantinople in 1453, and the Ottoman advance into Europe.