Raids into Byzantine and Persian territory by Arab tribesmen had long been a feature of life in the region, but it had been sporadic and usually desultory and had not previously been conducted by a unified Arab power. Moreover, by 633 the Byzantine and Persian empires were at a moment of unique weakness; having engaged from 602 to 628 in a mortal struggle that left Persia defeated and both empires thoroughly exhausted, neither was in good condition to recognize, react to, or cope with a serious invasion from another quarter. Yet that is exactly what confronted both powers.
Zoroastrian Persia, which Christian optimists had once hoped would become a Christian state due to the growing popularity of the faith in the region, was overrun and conquered in a series of campaigns carried out by Muslim Arabs between about 633 and 651 but it does not particularly concern us here. Christian Byzantium, exhausted though it was, had considerably more resilience, and a titanic struggle commenced between Muslims and Eastern Christians that would last from the 630s to May 29, 1453 (when Constantinople finally fell to the Ottoman Turks) and even beyond. This long history of attacks against Byzantine Christian territories by varying Muslim armies over the course of several centuries, which would ultimately result in the complete conquest of the Byzantine Empire, began only about fifteen months after the Prophet Muhammad’s death.
Indeed, Muhammad had envisioned Syria as the primary objective of Islamic expansion and had made provision for its invasion. Caliph Abu Bakr (r. 632–634) was left to carry out the project, launching a moderately successful raid in depth on southern Syria by an army of about 24,000 in the autumn of 633. A full invasion of this key province began in 634 under the leadership of Caliph Umar (r. 634–644). In 634 or 635 (sources differ), Damascus fell, and the Byzantine emperor Heraclius realized he had a serious situation on his hands. Scraping together all available troops, many of whom were Christian Arab auxiliaries, he sent out an army against the Muslim invaders. At the River Yarmuk, Heraclius’ army was decisively defeated and destroyed, leaving him with no choice but to cede Syria and withdraw. In 637 Antioch, in northern Syria, fell. The Muslims then turned their attention south, taking Byzantine-controlled Christian Jerusalem in 637 (or 638). Moving into Egypt, they occupied Alexandria in 642. The Byzantines counterattacked and recaptured Alexandria, but it fell again, and definitively, in 646.
Thus, in less than a decade, some of the most important cities of the Christian world—including three of its five great patriarchates (Jerusalem, Alexandria, and Antioch; Rome and Constantinople being the other two)—had fallen to Islamic conquerors, causing acute alarm among contemporary Christian authors. These were all important centers of the early Christian world. Saul of Tarsus had formalized his conversion to Christianity as Saint Paul in Damascus, and he had been let down over the wall in a basket to escape his enemies there; it was also the site of the magnificent Basilica of Saint John the Baptist (which would be converted into a mosque in the early eighth century).
Antioch was the place where Christians had first been given the very name “Christian” and the city where Peter, according to church tradition, had first served as bishop before moving to Rome. Saint Mark the Evangelist was associated with Alexandria, as were the later, influential Christian writers Origen and Saint Clement of Alexandria, and it was here that Patriarch Athanasius had, almost alone, withstood the heresy of Arius in the fourth century. And the loss of Jerusalem—the site of many of the most important events of the New Testament, including Christ’s crucifixion and resurrection, and the most important locus of Christian pilgrimage in Late Antiquity, the Middle Ages, and beyond—was particularly painful, not only spiritually but also emotionally. The reaction of Patriarch Sophronius of Jerusalem, upon seeing the Muslim leader Umar preparing a shrine on the Temple Mount, was typical: he is reported to have cried out, in anguish, “Truly this is the Abomination of Desolation spoken of by Daniel the Prophet, and it now stands in the Holy Place,” and to have burst into tears.
The loss of Syria, Palestine, and Egypt was crippling to Byzantium economically, politically, and militarily, but more blows to Christan lands were to come. Christian Axum (Ethiopia) and Nubia (Sudan), in northeast Africa, managed to beat off the first waves of Muslim attacks, which began as early as 640. Muslim advances against Nubia would recommence in the late thirteenth century, turning Nubia into a vassal state of Mamluk Egypt. The Christians of the Ethiopian highlands managed to hold out against Islam, although significant Muslim enclaves were established in the lowlands and along the coast during this later period. Muslim armies entered the Christian kingdoms of Armenia and Georgia in 642–643 and were in Cappadocia in {12} central Anatolia by 647. Cappadocia was the region where, in the first century, Saint Paul had lavished a great deal of missionary energy; later on, in the fourth century the important Eastern Christian fathers Saint Basil the Great, Saint Gregory of Nyssa, and Saint Gregory of Nazianzus had lived and written there, and Saint Macrina (older sister of Saints Basil and Gregory of Nyssa) had founded an influential convent of nuns there.37
Between 649 and 655, the formerly land-bound Arabs learned to use the resources of Alexandria to launch naval attacks on the Byzantines that progressively challenged the latter’s fleet, and in the Battle of the Masts off the southwestern coast of Anatolia (Asia Minor) in 655, the Muslim fleet decisively defeated the Byzantines and destroyed Byzantine naval superiority in the eastern Mediterranean.38 Nor were the central and western Mediterranean regions immune. With lightning speed, the Muslims exploited their position; they began to raid Byzantine Sicily as early as 652.
North Africa
In 647, Muslims who were advancing west from Egypt took Sufetula (modern Sbeitla in Tunisia) and put Carthage—the ancient city that had been home to two influential Christian writers, Tertullian and Saint Cyprian—in jeopardy; that city and its port fell in 698, and with it went Byzantine naval control of the western Mediterranean.
Here Muslims encountered a short-lived, but surprising, resistance from a shadowy figure: a Berber princess known as “the Kahina.” Whether she was pagan, Jewish, or (most probably) Christian is not entirely clear from the sources, but she rallied her people and managed what the imperial Byzantines seemed frequently incapable of in the seventh century—she rebuffed the Islamic armies, at least for a time. But the Muslim juggernaut was not to be delayed for long; by 702 or 703 the Kahina was dead, apparently killed in battle, as she herself took part in the fighting. According to an Islamic legend, in a gesture of despair, she sent her sons to join the enemy before her death at her last stand. In any case, the Muslims had already bypassed her and, as early as 670, had reached the Atlantic Ocean. When their commander, Uqba ibn Naf’i, reached the Atlantic, reflecting the intertwined nature of the Islamic faith with the goals of the conquerors, he was said to have ridden exultantly out into the waves, shouting, “Oh Allah! If the sea had not prevented me, I would have coursed on forever like Alexander the Great, upholding your faith and fighting all who disbelieved!”
Less than a generation after the Prophet’s death, Christian North Africa—home of theologians such as Saint Augustine and martyrs like Saints Felicity and Perpetua, who were central to the development of Christian tradition and thought, and rich with Christian history—had fallen to Islam. Along with Syria-Palestine and Anatolia, it had been the site of desert hermits and one of the birthplaces of Christian monasticism, home to the great and ancient patriarchate of Alexandria with its vast heritage of ancient learning, and the stage for the conflict between Catholic orthodoxy and two major heretical movements known as Arianism and Donatism, with all the theological developments that sprang from those conflicts.
The final version of the New Testament’s canon (the books approved as genuine) had been sent to the pope in Rome for confirmation by the Council of Carthage in 397. And the list goes on. In short, North Africa, from Egypt to present-day Morocco, was a vibrant and vital part of the pre-Islamic Christian world. Not all of its population was immediately converted to Islam—far from it. Large enclaves of Christians endured till the turn of the millennium or later, especially in Egypt, where perhaps 10 percent of the population remains Christian even today. Nevertheless, for all intents and purposes the deeply rooted public Christian culture of North Africa had been abruptly and violently suppressed by 700—by the armies of Islam.
Anatolia (Asia Minor) and the Aegean
Back in the eastern Mediterranean, Constantinople, the capital of the Eastern Roman (Byzantine) Empire and the most important Christian city in the world at the time, was fighting for its life. After 663, Muslim armies made near-annual raids into Anatolia, encroaching ever farther over the next fifteen years, soon reaching the Christian city of Chalcedon, situated across the Bosporus from Constantinople and the site of the historic Fourth Ecumenical Council in 451. The Muslims had been working toward controlling the islands of the Mediterranean and Aegean seas, and they established a base on the southern shore of the Sea of Marmara. Smyrna, farther south on the coast of Anatolia, fell in 672, leaving Islamic forces in control of most of the vast peninsula. By 674, a Muslim fleet was cruising outside Constantinople.
In following years their fleets returned, attempting to besiege and capture the city. In 678, the Byzantines, using their famous “Greek fire” apparently for the first time, drove the Islamic invaders off with heavy losses. A thirty-year truce was concluded, in theory at least, between the Muslim Arabs and the Christian Byzantines, which specified a heavy annual tribute to be paid by the Arabs to the emperor. For the first time, the tide had been stemmed and an important victory won. The Byzantine historian George Ostrogorsky saw it as critical:
The Arab attack . . . was the fiercest which had ever been launched by the infidels against a Christian stronghold, and the Byzantine capital was the last dam left to withstand the rising Muslim tide. The fact that it held saved not only the Byzantine Empire, but the whole of European civilization.
Alexander Vasiliev, another great Byzantine historian of the twentieth century, was of the same opinion: “By the successful repulse of the Arabs from Constantinople and by the advantageous peace treaty, [the Byzantines] performed a great service, not only for [the] Empire, but also for western Europe, which was thus shielded from the serious Muslim menace.”A number of historians have questioned whether the achievement was quite that far-reaching, but there is no question that the gateway to what we would call Eastern Europe and beyond had been held closed. For the moment.
But only for the moment, which was brief. Clashes resumed in 691, and in 709 the Muslims took an important fortress in Cappadocia, the heartland of Anatolia. During the next two years they made significant advances into Cilicia, the southeastern coastal region of Anatolia, bordering Syria. Tarsus, Cilicia’s capital city, was the birthplace of Saint Paul and home to a large number of early Christian martyrs. But worse was yet to come; in August 717, a great Muslim army and fleet appeared at Constantinople and settled down to besiege the city in earnest again, this time for an entire year.
