The House of Wisdom (5 page)

Al-Sulami understood that the crusaders were intent on holding Jerusalem and would seek to expand their control of the region to secure the city and its prized Church of the Holy Sepulcher. But
The Book of Holy War
also rightly identified the enemy’s vulnerabilities, in particular the crusaders’ long supply lines back to Western Europe. And it predicted that a united Muslim
ummah
, or community of believers, could successfully drive the invaders into the sea. “One knows for sure their weakness, the small amount of cavalry and equipment they have at their disposal and the distance from which their reinforcements come … It is an opportunity which must be seized quickly.”
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The Ifranj would soon discover just how prescient al-Sulami had been. The Army of God had failed to grasp that its remarkable military successes, however honestly won on the battlefield, were largely a reflection of the fractured, almost anarchic, state of affairs across Syria and Asia Minor. Within forty-five years, the Muslims began to roll back the Christian advances, a turn of events crowned by the triumphal entry into Jerusalem in 1187 of the political and military leader Saladin at the head of a unified force from Egypt and all of Syria.

Long supply lines and a unified Islam were not the only problems facing the Christian forces. Born in the West of iron and blood at the close of the eleventh century, the crusader movement immediately found itself deeply enmeshed in the life of the Muslim East in ways that would have horrified men like Peter the Hermit and Pope Urban II, who died just days before the news of Jerusalem’s capture could reach his sickbed in Rome. As countless attackers had before it, the Army of the Cross discovered that the very act of invasion and conquest left its mark on the besiegers as well as the besieged. There would be numerous campaigns to come—even the enduring mystery of the so-called Children’s Crusade of 1212, which, legend has it, ended in death by shipwreck or enslavement in Muslim lands—but the idea of crusade and crusading would never really be the same.

At first, such changes appeared relatively insignificant: Usama ibn Munqidh’s bemused accounts of how the Muslims had quickly begun to civilize the Europeans; or the way the Christians slipped so easily into the local factional disputes, even siding at times with Muslim warlords and against their coreligionists. Other, more powerful factors soon came to the fore, including the spectacular growth of East-West trade. The church clearly recognized the danger that such trade posed to its anti-Muslim agenda, and papal orders and outraged church councils periodically sought to crack down on commerce with the infidel, particularly in such strategic goods as wood for shipbuilding, iron, arms, and even foodstuffs.
⁵⁰

Still, money from this new trade with the East began to pour into the merchant leagues of southern Europe. Genoa came to dominate commerce with North Africa and the Black Sea region, while Venice maintained a money-spinning stranglehold on trade with Egypt and Syria.
⁵¹
Along with shipments of oil, perfumes, textiles, and precious metals came new ideas, technologies, and systems of thought. Our modern Arabic numerals were popularized in the West thanks in large measure to trade documents and contracts drawn up between Muslim merchants and their Italian counterparts. Trade terms in numerous European languages still bear the mark of Arabic and Persian commerical usage: for example, check, tariff, traffic, arsenal, and the French
douane
, or “customs.”
⁵²
Long-haul seaborne commerce required navigational aids, such as sophisticated maps, charts, and instruments, all areas where the medieval Muslims excelled. One measure of the growing economic ties between East and West was the appearance in European royal treasuries, as far away as England, of considerable quantities of Muslim gold. The minting of gold coins, halted in ninth-century Europe for lack of bullion, resumed in the Italian city-states four centuries later, once supplies from the East were secured.
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The new rulers of the Latin East soon began to realize that their own fates were bound up with those of the Muslims, Christian Arabs, Jews, and others who populated the region; there would be no significant reinfusion of European Christians to help colonize the crusader states. The ever-adaptable Normans took on the best aspects of Arab life even as they expelled Muslim rulers from the eastern Mediterranean, creating sumptuous courts whose learning and culture began to rival those of the great caliphs. At the same time the symbolic value of Jerusalem as a place worthy of fighting, slaughtering, and dying for began to fade—if only gradually—in the face of these new economic, political, and cultural realities.

Changes in the behavior and tactics of the crusaders were also striking. Later campaigns, which continued off and on for centuries, were either largely defensive affairs designed to claim territory already retaken by the Muslims or else perverted by raw political ambition and outright greed, such as the sack of Christian Constantinople in 1204 at the instigation of the powerful merchants of Venice. One “Crusade” involved a negotiated and temporary transfer of authority over Jerusalem, a favor by Muslim sultan to Christian king—a circumstance few could have predicted at the time of Clermont. At other times, crusading armies were offered control of Jerusalem, once the object of their most fervent desires, in exchange for Muslim territory seized elsewhere; they declined only to leave the Near East empty-handed.

The steady success of Christian forces in Spain and the reemergence of Christian military power in the Mediterranean, especially the capture by the Normans of once-Muslim Sicily, had already brought the worlds of Islam and Christendom into close contact and direct competition. But the First Crusade opened a third pathway between East and West, one in which brute military struggle would slowly give way to a web of commercial, cultural, and intellectual bonds between two rival but ultimately inseparable worlds. By the time Adelard of Bath arrived in Antioch around 1114, Arab culture—if not Muslim military might—held sway over much of life in the so-called Latin East.

Chapter Two

THE EARTH IS LIKE A WHEEL

S
EVEN YEARS BEFORE
the earthquake that shook the moral foundations of crusader Antioch, Adelard surveyed the world around him and pronounced it rotten. His recent studies at the famed French cathedral school at Tours had provided him with the best education of his day. He enjoyed the support and patronage of the powerful bishop of Bath, the French court physician and scholar John de Villula. He practiced the art of hunting with falcons, a sign of his noble rank and the life of leisure it generally afforded. And he was an accomplished musician, who years later still fondly recalled the time he had been invited to play the
cithara
, a forerunner of the guitar, for the queen.

In short, Adelard of Bath was the model country gentleman. His father, Fastrad, was one of Bishop John’s richest tenants and most senior aides, ensuring a life of privilege for his son. The family appears sporadically in official documents of church and state. The Pipe Rolls, or royal accounts, later list Adelard as the beneficiary of a pension from the revenues of Wiltshire, in southwest England. Still, young Adelard saw little of value in the contemporary world, and he despaired at the state of Western learning in particular. “When I examine the famous writings of the ancients—not all of them, but most—and compare their talents with the knowledge of the moderns, I judge the ancients eloquent, and call the moderns dumb,” he proclaimed in the opening line of his coming-of-age essay and first known work,
On the Same and the Different
.
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Adelard’s disdain for “the moderns” was understandable, for the West at the end of the eleventh century was a mess. Daily life staggered under the burden of rampant violence and social instability. Bands of mercenaries, answerable to neither king nor God, prowled the countryside, their commanders’ word the only law of the land. Across Europe, primitive farming techniques could no longer keep pace with a growing population, while antiquated inheritance laws left many impoverished and desperate.
²
Violence—inflamed by the weakness of central political authority and uninhibited by the tenuous moral grip of the Catholic Church—was the currency of the day. As Pope Urban II had acknowledged at Clermont when he called for the First Crusade, religious leaders were helpless to halt the chaos across the continent. The best the church could do was to redirect its flock’s baser nature against the infidels to the East.

Not even Adelard’s remote corner of England was immune to the troubles. It was not long since the Norman Conquest of 1066, and political and social strife still plagued the land. The uneasy relationship—for centuries punctuated by bouts of armed conflict—between what today comprise the distinct nations of England and France was a regular feature of late medieval life. At the same time, political, cultural, and personal ties ran deep, and so it was not surprising that Adelard could pursue higher education in Tours and that many leading officials and courtiers, like Bishop John, hailed from the European mainland. In 1086, as a young child, Adelard had seen his native West Country town, including its once-proud abbey of black-robed monks, burned almost to the ground during an uprising against the heir to the throne, William the Red. The rebels had hoped to secure the rule of William’s brother, Robert of Normandy, but their bid for power had ended in bloody failure and considerable destruction. Robert, eldest son of William the Conqueror, later died a royal prisoner.

Things were little better inside the elite cathedral schools. The chaos and disorder that had swept in with the Germanic invasions of the western Roman Empire, beginning in the fourth century
A.D.
, had just about destroyed formal education and the perpetuation of classical knowledge. The Muslim conquests around the eastern Mediterranean three hundred years later sealed the West’s isolation by choking off easy access to the Byzantine Christians based in far-off Constantinople, where some traces of the Greek intellectual tradition could still be found.
³
The wonders of classical learning were all but forgotten, or at best pushed to the extreme margins of European consciousness. Invaluable texts were lost through inattention, destroyed in war, or rendered unintelligible by the general ignorance of would-be scholars or simply by the lost ability to read Greek. The aristocracy of the Roman Empire read the Greek masters in the original, so there was no need at the time for Latin translations of the philosophy of Plato and Aristotle, the engineering wonders of Archimedes, or the geometry of Euclid. The wholesale disappearance of Greek as the language of learning meant centuries of knowledge virtually vanished from the collective mind of Latin-speaking Europe.

There were a few outposts—scattered monasteries in Ireland, northern England, Catalonia, and southern Italy—where the monks labored to keep the classical traditions alive. Yet the results were meager in comparison with the heights once scaled by the Greeks, or with the new and exciting work being carried out in the Arab world. At the West’s leading center of mathematical studies, the cathedral school of Laon, the best minds of Adelard’s day had no grasp of the use of zero. The masters at Laon taught the latest techniques employed by King Henry I, who ruled both England and Normandy in the early twelfth century, to manage his treasury. These included the use of a special tablecloth, marked out in rows and columns like a chessboard and based on the principles of the abacus, which had reached France from Arab Spain some years before. The cloth was known as the
scaccarium
, Latin for “chessboard,” and was the origin of the English term for a national treasury,
exchequer
. Despite the importance of this royal mission, the standard of learning at Laon remained very low; one contemporary textbook reveals consistent errors in even the most basic calculations.
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More vexing than sloppy royal accounting was the inability to measure the hours of the day or keep the calendar. Even by the sleepy standards of medieval Christendom, time was a serious business, linked as it was with the pursuit of heavenly salvation. The Rule of St. Benedict, which governed thousands of monasteries from the sixth century onward, required eight sets of prayers at specific times every twenty-four hours. The practice was based on a reading of two verses in Psalm 119: “Seven times a day I praise thee” and “At midnight I rise to give thee thanks.”
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This was relatively simple during the day, when the changing position of the sun could provide a rough guide to the hour, but at night the monks of the Latin West were left literally in the darkness of their own ignorance.

Crude methods of timekeeping evolved to fulfill the demands of the rule. It was found, for example, that a twelve-inch wax candle of a certain diameter would last about four hours.
⁶
A handful of the more prosperous monasteries employed elementary water clocks, in which the regulated flow of water into a container measured the passage of a given unit of time. In an early example of practical astronomy, the sixth-century prelate Gregory of Tours offered a rule of thumb, possibly Babylonian in origin, that accounted for the changing length of the days by beginning at nine hours of daylight in December and adding one hour per month from December to June, to make fifteen hours. The process was then reversed from June back to December. Popular in its day for its simplicity and ease of use, the system is nonetheless undermined by a lack of scientific understanding: The ratio of fifteen to nine is better suited to the latitudes of the Mediterranean and the Near East than it is to the northern climes of Tours.
⁷
Gregory presented a similar method for keeping track of the changing phases of the moon through the course of the month, but he made no provisions for seasonal changes. And he identified some constellations in the northern sky—taking pains not to use their pagan names—that could be used on clear nights to help regulate the prayers.
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