INTRODUCTION

Large rocks, severed heads, and flaming pots of oil rained down on Baghdad, capital of the vast Islamic Empire, as its weary defenders scrambled to reinforce gates, ditches, and the massive stone walls surrounding the fortress city's many brick and teak palaces. Giant wooden manjaniq catapults bombarded distant structures while the smaller, more precise arradah catapult guns pelted individuals with grapefruit-sized rocks. Arrows flew thickly and elite horsemen assaulted footmen with swords and spears. "The horses . . . trample the livers of courageous young men," lamented the poet al-Khuraymi, "and their hooves split their skulls." Outside the circular city's main wall—100 feet high, 145 feet thick, and six miles in circumference—soldiers pressed forward with battering rams while other squads choked off supply lines of food and reinforcements. Amid sinking boats and burning rafts, bodies drifted down the Tigris River.

The impenetrable "City of Peace" was crumbling. In the fifty years since its creation in A.D. 762, young Baghdad had rivaled Constantinople and Rome in its prestige and influence. It was a wildly fertile axis of art, science, and religion, and a bustling commercial hub for trade routes reaching deep into Central Asia, Africa, and Europe. But by the late summer of A.D. 813, after nearly two years of civil war (between brothers, no less), the enlightened Islamic capital was a smoldering, starving, bloody heap.

In the face of disorder, any human being desperately needs order—some way to manage, if not the material world, at least one's understanding of the world. In that light, perhaps it's no real surprise that, as the stones and arrows and horses' hooves thundered down on Baghdad, the protected core of the city hosted a different sort of battle. Within the round city's imperial inner sanctum, secure behind three thick, circular walls and many layers of gate and guard, under the luminescent green dome of the Golden Gate Palace, Muhammad al-Amin, the sixth caliph of the Abbasid Empire, spiritual descendant of (and distant blood relation to) the Prophet Muhammad, sovereign of one of the largest dominions in the history of the world, was playing chess against his favorite eunuch Kauthar.

A trusted messenger burst into the royal apartment with urgently bad news. More inglorious defeats in and around the city were to be reported to the caliph. In fact, his own safety was now in jeopardy.

But al-Amin would not hear of it. He waved off his panicked emissary.

"O Commander of the faithful," implored the messenger, according to the medieval Islamic historian Jirjis al-Makin. "This is not the time to play. Pray arise and attend to matters of more serious moment."

It was no use. The caliph was absorbed in the board. A chess game in progress is—as every chess spouse quickly learns—a cosmos unto itself, fully insulated from an infant's cry, an erotic invitation, or war. The board may have only thirty-two pieces and sixty-four squares, but within that confined space the game has near-infinite depth and possibility. An outsider looking on casually might find the intensity incomprehensible. But anyone who has played the game a few times understands how it can be engrossing in the extreme. Quite often, in the middle of an interesting game, it's almost as if reality has been flipped inside out: the chess game in motion seems to be the only matter of substance, while any hint of the outside world feels like an annoying irrelevance.

The messier the external world, the more powerful this inverted dynamic can be. Perhaps that is why Caliph al-Amin, who sensed that his hours were numbered, preferred to soak in the details of his chess battlefield rather than reports of the calamitous siege of his city. On the board he could see the whole action. On the board he could neatly make sense of significant past events and carefully plan his future. On the board he still might win.

"Patience my friend," the caliph calmly replied to his messenger standing only a few feet away and yet a world apart. "I see that in a few moves I shall give Kauthar checkmate."

Not long after this, al-Amin and his men were captured. The sixth Abbasid caliph, victor in his final chess game, was swiftly beheaded.

Chess lived on. The game had been a prominent court fixture of Caliph al-Amin's predecessor, and would voraciously consume the attention of his successor—and the caliph after that, and the caliph after that. Several centuries before it infected feudal Christian Europe, chess was already an indelible part of the landscape adjoining the Tigris and Euphrates. This simple game, imbued with a universe of complexity and character, demanded from peasants, soldiers, philosophers, and sovereigns an endless amount of time and energy. In return it offered unique insights into the human endeavor.

And so, against all odds, it lasted. Games, as a general rule, do not last. They come and go. In the eighth century, the Irish loved a board game called fidchell. Long before that, in the third millennium B.C., the Egyptians played a backgammonlike race game called senet. The Romans were drawn to duodecim scripta, played with three knucklebone dice and stacks of discs. The Vikings were obsessed with a game called hnefatafl in the tenth century, in which a protagonist King attempted to escape through a ring of enemies to any edge of the board. The ancient Greeks had petteia and kubeia. These and hundreds of other once popular games are all now long gone. They caught the public imagination of their time and place, and then for whatever reason lost steam. Generations died off, taking their habits with them; or conquering cultures imposed new ideas and pastimes; or people just got bored and wanted something new. Many of the games fell into such total oblivion that they couldn't even make a coherent mark in the historical record. Try as they might, determined historians still cannot uncover the basic rules of play for a large graveyard of yesterday's games.

Contrast this with chess, a game that could not be contained by religious edict, nor ocean, nor war, nor language barrier. Not even the merciless accumulation of time, which eventually washes over and dissolves most everything, could so much as tug lightly at chess's ferocious momentum. "It has, for numberless ages," wrote Benjamin Franklin in 1786, "been the amusement of all the civilized nations of Asia, the Persians, the Indians, and the Chinese. Europe has had it above 1000 years; the Spaniards have spread it over their part of America, and it begins lately to make its appearance in these States."

The game would eventually pass into every city in the world and along more than 1,500 years of continuous history—a common thread of Pawn chains, Knight forks, and humiliating checkmates that would run through the lives of Karl Marx, Pope Leo XIII, Arnold Schwarzenegger, King Edward I, George Bernard Shaw, Abraham Lincoln, Ivan the Terrible, Voltaire, King Montezuma, Rabbi Ibn Ezra, William the Conqueror, Jorge Luis Borges, Willie Nelson, Napoleon, Samuel Beckett, Woody Allen, and Norman Schwarzkopf. From Baghdad's Golden Gate Palace to London's Windsor Castle to today's lakeside tables at Chicago's North Avenue Beach, chess would tie history together in a surprising and compelling way.

How could a game last so long, and appeal so broadly across vast spans of time, geography, language, and culture? Endurance is not, of course, a magnificent accomplishment in itself, but a compelling sign that something profound is going on, a catalytic connection between this "game" and the human brain. Another sign is that chess was not just played but also integrated into the creative and professional lives of artists, linguists, psychologists, economists, mathematicians, politicians, theologians, computer scientists, and generals. It became a popular and pliable metaphor for abstract ideas and complex systems, and an effective tool through which scientists could better understand the human mind.

The remarkable scope of this game began to infect my own brain after a visit from an old family ghost in the fall of 2002. My mother had sent on some faded newspaper clippings about her great-grandfather, my great-great-grandfather, a diminutive Polish Jew named Samuel Rosenthal who immigrated to France in 1864 and became one of its legendary chess masters. Family lore had it that Rosenthal had impressed and/or somehow secured the gratitude of one of the Napoleons, and had been awarded a magnificent, jewel-encrusted pocket watch. No one in the family seemed to have actually seen this watch, but they'd all heard about it. Four generations down the line, this story, retold to a boy from the Ohio suburbs, was just exotic enough, and just hazy enough, to set the mind racing. I had begged Mom for years to tell me more about the great S. Rosenthal and his lost watch.

As I combed through the records on my mother's mother's father's father's achievements, wondering what spectacular (if still hidden) intelligences had filtered down through the generations, I also became reacquainted with the game itself, which I had not played since high school (and then only a handful of times). Stumbling through a few dozen games with friends at home and with strangers over the Internet, I found that I was just as ambivalent about chess as I'd been twenty years earlier—charmed by its elegance and intrigued by its depth, but also put off by the high gates of entry to even moderately serious play. Graduating from patzer to mere competence would require untold hundreds of hours of not just playing but studying volumes of opening theory, endgame problems, and strategy. Years of obsessive attention to the game might—might—eventually gain me entry into reasonably serious tournaments, where I would no doubt be quickly dispatched by an acid-tongued, self-assured ten-year-old. Chess is an ultimately indomitable peak that gets steeper and steeper with every step.

I was also repelled, frankly, by the forbidding atmosphere of unforgiving rules, insider jargon, and the general aggressiveness and unpleasantness that seemed to accompany even reasonably casual play. I recalled one of Bobby Fischer's declarations: "Chess is war over the board," he proclaimed. "The object is to crush the opponent's mind." Fischer was not alone in his lusty embrace of chess's brutality. The game is often as much about demolishing your opponent's will and self-esteem as it is about implementing a superior strategy. No blood is drawn (ordinarily), but the injury can be real. The historical link between top chess play and mental instability stands as yet another intriguing feature about the game and its power. "Here is nothing less," writes recovering chess master Alfred Kreymborg, "than a silent duel between two human engines using and abusing all the faculties of the mind. . . . It is warfare in the most mysterious jungles of the human character."

Still, much to my wife's dismay, I got hooked. It is an intoxicating game that, though often grueling, never grows tiresome. The exquisite interplay of the simple and the complex is hypnotic: the pieces and moves are elementary enough for any five-year-old to quickly soak up, but the board combinations are so vast that all the possible chess games could never be played—or even known—by a single person. Other parlor games sufficiently amuse, entertain, challenge, distract; chess seizes. It does not merely engage the mind; it takes hold of the mind in a way that suggests a primal, hardwired connection.

Even more powerfully, though, I became transported by chess's rich history. It seemed to have been present in every place and time, and to have been utilized in every sort of activity. Kings cajoled and threatened with it; philosophers told stories with it; poets analogized with it; moralists preached with it. Its origins are wrapped up in some of the earliest discussions of fate versus free will. It sparked and settled feuds, facilitated and sabotaged romances, and fertilized literature from Dante to Nabokov. A thirteenth-century book using chess as a guide to social morality may have been the second-most popular text in the Middle Ages, after the Bible. In the twentieth century, chess enabled computer scientists to create intelligent machines. Chess has also, in modern times, been used to study memory, language, math, and logic, and has recently emerged as a powerful learning tool in elementary and secondary schools.

The more I learned about chess's peculiarly strong cultural relevance in century after century, the more it seemed that chess's endurance was no historical accident. As with the Bible and Shakespeare, there was something particular about the game that made it continually accessible to generation after generation. It served a genuine function—perhaps not vital, but often far more than merely useful. I often found myself wondering how particular events or lives would have unfolded in chess's absence—a condition, I learned, that many chess haters had ardently sought. Perhaps the most vivid measure of chess's potency, in fact, is the determination of its orthodox enemies to stamp it out—as long ago as a ruling in 655 by Caliph Ali Ben Abu-Talib (the Prophet Muhammad's son-in-law), and as recently as decrees by Ayatollah Ruhollah Khomeini in 1981, the Taliban in 1996, and the Iraqi clergy in post-Saddam Iraq. In between, chess was tamped down:

in 780 by Abbasid Caliph al-Mahdi ibn al-Mansur
in 1005 by Egypt's al-Hakim Bi-Amr Allah
in 1061 by Cardinal Damiani of Ostia
in 1093 by the Eastern Orthodox Church
in 1128 by St. Bernard
in 1195 by Rabbi Maimonides
in 1197 by the Abbot of Persigny
in 1208 by the Bishop of Paris
in 1240 by religious leaders of Worcester, England
in 1254 by King Louis IX of France (St. Louis)
in 1291 by the Archbishop of Canterbury
in 1310 by the Council of Trier (Germany)
in 1322 by Rabbi Kalonymos Ben Kalonymos
in 1375 by France's Charles V
in 1380 by Oxford University's founder William of Wickham
in 1549 by the Protohierarch Sylvester of Russia
and in 1649 by Tsar Alexei

But like the Talmud, like the theory of natural selection, like any organized thought paradigm that humans have found irresistibly compelling, chess refused to go away. Why were sixty-four squares and a handful of generic war figurines so hard to erase from the human imagination? What was it about chess that drew simultaneous devotion and disgust, and sparked so many powerful ideas and observations over many centuries?

This is what I set out to understand, through a close survey of chess's history and a fresh look at the game.