Osama bin Laden called America's response to September 11, a "new crusade and Jewish campaign led by the big crusader Bush under the flag of the cross." He clearly meant to link the military campaign to European campaigns from a millennium ago, during which, the prevailing mentality holds, Christian warriors unjustly attacked Islamic possessions in and around Palestine.

By establishing this connection, though, the fugitive fanatic admits more than he alleges. In the Middle Ages, as in 2001, Islam struck first—and in such a way that the West would certainly respond.

Waves of conquest

Jerusalem has changed hands many times over the centuries, but the seventh century was particularly tumultuous. Pagan Persians stormed the city in 614. Eastern Christians, led by Byzantine Emperor Heraclius, reclaimed it by 630. Within a few years, though, Islamic forces had broken the Byzantine military and chased them out of Palestine.

Jerusalem surrendered to a Muslim army in 638. Construction began soon afterward on a mosque at the Temple Mount. Sophronicus, the patriarch of the city, is said to have burst into tears and wailed, "Truly this is the Abomination of Desolation spoken of by Daniel the Prophet!"

After capturing Jerusalem, the Muslim armies poured through the eastern and southern provinces of the reeling Byzantine Empire. In the 640s Armenia in the north and Egypt in the south fell to Islam. In 655 the Muslims won a naval battle with the Byzantines and very nearly captured the Byzantine emperor.

By 711 Muslims controlled all of northern Africa, and a Muslim commander named Tariq had set foot on European soil—on a rock that took his name (Jebel al-Tariq, corrupted into Gibraltar). By 712 Muslims had penetrated deep into Christian Spain. At the battle of Toledo that year, they defeated the Spanish and killed their king. The Spanish kingdom promptly collapsed.

Surviving Christians retreated into the mountains of northwestern Spain and dug in their defenses. The Muslim armies bypassed them and began raiding across the Pyrenees into France.

Meanwhile, in the East, Muslims continued to push into the Byzantine Empire. By 717 they had landed in southeastern Europe, and they besieged the Byzantine capital, Constantinople. Had they taken the city, they might have conquered the entire continent. But the Byzantines resisted. Their capital would not fall to Islam until 1453.

Western Christians stopped the Muslim advance into their territory in 732 at the Battle of Tours (or Poitiers), France. Charles of Heristal, Charlemagne's grandfather, led a Frankish army against a large Muslim raiding party and defeated them, though Muslim raiders would continue attacking Frankish territory for decades. For his victory, Charles became known as the Hammer—in French, Charles Martel.

After regrouping, Muslim forces began to move into south central Europe, lauching invasions of Sicily, Sardinia, and Corsica in the ninth century. They mounted operations on the Italian mainland as well, sometimes at the invitation of quarrelling Christian powers.

In 846 Muslim raiders attacked the outlying areas of Rome, the center of western Christianity. This act would be comparable to Christians sacking Mecca or Medina, something they have never done.

Toward the end of the ninth century, Muslim pirate havens were established along the coast of southern France and northern Italy. These pirates threatened commerce, communication, and pilgrim traffic for a hundred years or more.

During the tenth century, however, the tide began to turn. In the East in the 950s and 960s, the Byzantines mounted a series of counterattacks. They eventually recovered the islands of Crete and Cyprus and a good bit of territory in Asia Minor and northern Syria, including Antioch. They lacked the strength to retake Jerusalem, though they might have struggled harder had they known what terrors the city would soon face.

New threats

In 1000, much—perhaps even most—of the population of the Holy Land was still Christian, of one affiliation or another. This was about to change.

One reason was the rise of a local Muslim ruler named Hakim, who was possibly insane and certainly not an orthodox Muslim (he claimed to be divine). Hakim persecuted Christians and Jews fiercely. In 1009 he ordered the destruction of the rebuilt Church of the Holy Sepulchre in Jerusalem. The Christian population of the Holy Land began to shrink under his tyrannical rule.

Hakim aroused great hostility even from other Muslims, and his reign was soon over. The Byzantines, distressed by the damage to the Church of the Holy Sepulchre, negotiated with the Muslims and in 1038 were allowed to begin rebuilding it again. But the losses to the local Christian (and Jewish) communities were harder to repair.

Another, and perhaps more serious, cause of distress for the local populations of all faiths was the intrusion into the Middle East of the Seljuk Turks. The Seljuks, pagan nomads from the steppes of central Asia, made steady inroads into the more sophisticated world of the Muslim Arabs in the early eleventh century.

In 1055, the Seljuks captured Baghdad, destroying a long-lived Muslim dynasty and seriously disrupting the stability of the Middle East. This might have provided an opportunity for the Christian Byzantines to recover their lost provinces, but even as the Seljuk Turks conquered the Arabs, they converted to Islam. The Muslim Arab overlords of the region were thus replaced by harsher, coarser Muslim Turks.

Pleas from the East

In 1071 Byzantine Emperor Romanus Diogenes confronted a Turkish invasion force in the far eastern provinces of the Byzantine Empire. The two armies met at the village of Manzikert, near Lake Van, and the Byzantines were utterly defeated. As a result of this disaster, the Byzantines lost all the territory that they had recovered, painstakingly, in the ninth and tenth centuries. This included the entirety of Asia Minor, the breadbasket and recruiting ground of the empire.

Succeeding Byzantine emperors sent frantic calls to the West for aid, directing them primarily at the popes, who were generally seen as protectors of Western Christendom. Pope Gregory VII received these appeals first, and in 1074 he discussed leading a relief expedition to Byzantium himself. But this proved impractical, and no aid was offered. The Byzantines continued sending appeals, however, eventually finding an audience with Pope Urban II.

In the meantime, Turkish invasions continued to affect the Holy Land. Jerusalem, which was held by the Shi'ite Fatimid dynasty of Egypt, was captured by the Seljuk Turks in 1071. The Turks, suspecting (rightly or wrongly) that the local Christian population might prefer their former Fatimid rulers to the new overlords, persecuted them. In 1091, Turks drove out the Christian priests.

The Fatimids, meanwhile, bided their time. When the moment was right, they seized the city again—in 1098, just one year before the First Crusade would arrive to recapture it.

In 1095, the West finally responded to the plight of Eastern Christians by mounting the First Crusade. In 1099, crusaders stormed Jerusalem. Like the capture of Jerusalem by the Persians in 614, but unlike the negotiated surrender to the Muslims in 638, this attack ended in a bloody massacre of the city's inhabitants. "Heaps of heads and hands and feet were to be seen throughout the streets and squares of the city," a medieval historian wrote.

A Christian kingdom controlled much of the Holy Land until 1291, when the Muslims once again conquered the area. But the crusades themselves were military failures. Whatever battles Christians could claim, Muslims would win the war.

Islam strikes back

The recapture of Jerusalem by Christian forces in 1099 did not, at first, draw much notice from the Muslim world. A few poets wrote laments on its capture. Abu l-Muzaffar al-Abiwardi, an Iraqi poet, called for a response:

Sons of Islam, behind you are battles in which heads rolled at your feet.

Dare you slumber in the blessed shade of safety, where life is as soft as an orchard flower? …

This is war, and the man who shuns the whirlpool to save his life shall grind his teeth in penitence.

The titular supreme ruler of the Islamic world, the caliph of Baghdad, also issued a statement of regret. But in general, local Muslim rulers adapted to the presence of the Christian rulers of the crusader states just as they had adapted to the intrusion of the Turks: here were new players on the stage of the Middle East.

Before long, that began to change. A series of Muslim rulers, including Zengi, Nur al-Din, and the famous Saladin, fought to reunite the fractured parts of the Islamic Middle East. These leaders initiated a jihad, a counter-crusade against the Christians of Jerusalem and the surrounding regions. A desire to reconquer the city figured more and more notably in Muslim writings.

By the end of the twelfth century, Saladin had reconquered Jerusalem more or less permanently. The entire Holy Land was back under Islamic control by 1291.

Christians repeatedly tried to launch crusades to drive back the renewed Muslim assault, but these attempts all failed. Crusading was too difficult, dangerous, and costly. Besides, the growing kingdoms of Europe were more interested in their own affairs than they were in the fate of Jerusalem or of Eastern Christians.

Europe under siege

By the fourteenth century, a new Muslim force had appeared in Asia Minor: the Ottoman Turks. Brought into southern Europe by one side in a Byzantine civil war, the Ottomans quickly established a base from which to expand.

Christian Balkan powers began to fall before the Ottoman advance. Christian leaders like Prince Lazar of Serbia, John Hunyadi of Hungary, and the Albanian guerilla commander Skanderbeg put up a heroic resistance, but in vain. The drumbeat of Muslim advance had resumed.

Lazar was defeated and killed in the first battle of Kosovo in 1389. Bulgaria was overrun in 1393. John Hunyadi was defeated in 1448 at the second battle of Kosovo while trying to mount a campaign to save the beleaguered Byzantines, who by now were virtual prisoners inside their capital city of Constantinople.

Constantinople was sacked in May 1453. The last Byzantine emperor, Constantine XI, died in desperate fighting around the gates of the city.

Legend has it that an Orthodox priest was celebrating mass in the Cathedral of Holy Wisdom (Hagia Sophia) when Muslim troops broke in. He escaped by walking miraculously into the altar, from whence, according to the legend, he will return once Constantinople is Christian again.

The legend is doubtless just that. But no more Christian services were conducted in the cathedral—Hagia Sophia, like most of the other churches of Constantinople, was converted into a mosque.

Over the next 200 years, European strength grew to match, then exceed, Islamic power. European states also began to claim colonies around the globe. Muslims lost their grip on land-based Asian trade and never developed the naval technology to keep pace with Europeans at sea.

In 1683, the Ottomans launched a final attack on Europe, staging their second siege of Vienna (the first took place in 1529). Once again, the city seemed on the verge of falling. It was saved by what may have been the last true crusade.

A Polish force, led by Jan Sobieski, caught the Turks by surprise and relieved the siege. Sobieski also, it is said, brought coffee and croissants onto Western tables when he discovered the Turks' uneaten breakfasts in their tents.

Muslims made no more serious attempts to take the city, or any other territory in Europe. The Muslim world was slipping into a long period of decline from which it is only now emerging.

Crusades reconsidered

Though some Christians decried the crusades while they were happening (see page 28) and soon afterward (see page 31), anguish over this episode in history dates primarily from more recent years. In the early 1950s, at the end of his sweeping three-volume history of the crusades, Sir Steven Runciman put it this way: "The Crusades were a tragic and destructive episode. The Holy War itself was nothing more than a long act of intolerance in the name of God, which is the sin against the Holy Ghost."

Muslims, too, have lately taken a darker view of the crusade era. Until relatively recently, they saw the battles as episodes in the long contest between Islam and Christianity—a contest initiated by Islam. Now, statements like this, from Lebanese journalist Abin Maalouf in the 1980s, are more common: "[T]here can be no doubt that the schism between these two worlds [of Islam and Christianity] dates from the crusades, deeply felt by the Arabs, even today, as an act of rape."

In the late 1990s, an American child led a "Reconciliation Walk" across Europe and the Middle East, distributing hugs, apologies, and a written statement, saying, "We deeply regret the atrocities committed in the name of Christ by our predecessors" to the bemused Muslims he and his companions met along the way.

The child's activities fit into a larger pattern of Western amnesia about the conflict between Islam and Christianity, and of fashionable Western self-loathing. Muslims have offered no apologies. Some Muslim leaders still call the faithful to counter-crusade today, viewing themselves as continuing the tradition of Muslim conquest of Christian lands (though many of those lands have ceased to be Christian in any meaningful way). Muslims in general seem to have accepted the Christians' self-description as unjust aggressors.

But if Christians are allowed to wage war when attacked, and if Christians believe that their religion has a right to exist outside the sphere of Islamic law, perhaps modern Christians should take a second look at the crusades and their historical context, in which Christianity was under near-constant pressure from the Islamic world from the seventh century to the seventeenth.

Paul Crawford is assistant professor of history at Alma College in Alma, Michigan. He specializes in ecclesiastical history with emphasis on the crusades and military orders.