War: What is it good for?

by Ian Morris

  Almost everywhere—but not quite everywhere. The big exception to the rule of third-century imperial collapse was Persia, where, after overthrowing the Parthians in A.D. 224, the new Sasanid dynasty went from strength to strength. It smashed Kushan and Roman armies, rolled back the steppe nomads, and centralized power. By 270, when the great conqueror Shapur I died, the Sasanid capital at Ctesiphon was one of the world’s grandest cities.

  But on closer inspection, the Sasanid exception turns out not to have been an exception at all, because the rule in these years was not simply one of imperial collapse. Rather, the twelve hundred years between roughly A.D. 200 and 1400 were an age of cycles of productive and counterproductive wars. As we saw in Chapters 1 and 2, the millennia leading up to A.D. 200 were an era of expanding Leviathans, rising prosperity, and falling rates of violent death, and as we shall see in Chapters 4–7, this is even truer of the centuries since 1400. But the long Middle Ages separating these two periods constituted a complicated, messy, and violent interlude.

  It is a tangled story. For a while in the late third century it looked as if the Sasanid revival were actually the first example of a new trend toward imperial recovery. After half a century of anarchy, Rome had regained control over the whole Mediterranean Basin by 274, the Western Jin dynasty had reunited China into a single empire by 280, and in the 320s the Gupta dynasty had begun doing the same in India. By then, though, the recovery was already ending in other parts of Eurasia. Xiongnu nomads burned China’s ancient cities, executed a string of Western Jin emperors, and massacred millions of refugees. Sixty years of fighting followed, until in 383 it looked as if a new dynasty were about to unite China once again; but its army mysteriously dissolved in panic after a minor defeat, and another cycle of slaughter engulfed East Asia.

  Rome too slid back toward chaos in the late fourth century. Goths destroyed the empire’s field armies at Adrianople in 378 and the frontiers began dissolving. Westward migrations of Huns (the most terrifying of all the ancient nomads) toppled more dominoes, and on New Year’s Eve 406, thousands of Germans flooded across the frozen Rhine River. Western Europe spiraled down into violence and chaos, and in 476—just seventy years after the Rhine frontier failed—a Germanic king announced that the western half of the Roman Empire had ceased to exist.

  In 484, it looked as if Sasanid Persia would go the same way when another branch of the Huns wiped out its army and killed its king. But the Sasanids hung on, and by this time China too was moving back toward unity. In the fifth century another new dynasty reunited the Yellow River region, and in 589 the Sui dynasty finally brought the whole of China back under a single government.

  For a few giddy years, the Mediterranean also seemed to be swinging back toward unity. In the 520s, Justinian, ruler of the Byzantine Empire—as the surviving (eastern) portion of the old Roman Empire is often called—won back Italy and parts of Spain and North Africa. By 550, though, expansion had stalled, and in the later sixth century fresh invasions rolled the Byzantines back. India had an equally rough ride: after 467 the Gupta Empire started disintegrating in the face of attacks from another branch of the Huns, and despite a great victory over the nomads in 528, by 550 the empire was to all intents and purposes history. And on it went, century after chaotic century, all across Eurasia’s lucky latitudes.

  I have not tried to tidy up the fact that this is a confusing narrative, and I think that Figure 3.6 sums up its messiness nicely. The graph divides the lucky latitudes into four regions (Europe, the Middle East, China, and India) and charts the geographical size of the biggest empire in each across the first fourteen centuries A.D. Admittedly, there are all kinds of technical problems in simply using size as a measure of Leviathanness (by which I mean the strength of centralized government). The most obvious is the great spike in the Middle Eastern curve between A.D. 650 and 850, representing the Umayyad and Abbasid caliphates established by the Arabs. In theory, the caliphs ruling from Damascus and Baghdad controlled 4.3 million square miles, one of the biggest empires in history, but in practice hardly anyone outside Syria and Iraq took much notice of them. The Indian spike around A.D. 150, representing the Kushan Empire, raises another problem: the Kushans ruled 2.3 million square miles, but most of these square miles had hardly anyone living in them.

  Figure 3.6. One damned thing after another? The rise and fall (and rise, and fall) of Leviathans in Eurasia’s lucky latitudes, as reflected by the size of the largest state in each region, A.D. 1–1400

  But despite these (and other) issues, this tangled graph does make one big point. Between the second century and the fourteenth, there were few years when every part of the lucky latitudes was moving in the same direction. For every empire that rose, another fell. One society’s golden age was another’s dark age.

  What does this mean? The obvious interpretation, and the one most favored by historians, is—as the brilliant polymath Arnold Toynbee put it back in the 1950s—that the past is simply “a chaos unamenable to [scientific] laws; a meaningless succession of events that a twentieth-century novelist who was also poet laureate called Odtaa, standing for ‘one damned thing after another.’” On the face of it, Figure 3.6 looks like the poster child for Odtaa. Empires rise and fall, battles are won and lost, but nothing much changes. Everything is an exception to everything else.

  Toynbee, however, conjured up the image of Odtaa only to dismiss it. After spending decades studying world history, he knew perfectly well that the story is full of big patterns that go beyond Odtaa, and I think he would have seen several such patterns in this graph. First, he might have observed, there is an obvious trend here, which Figure 3.7 draws out. Behind all the noise, the size of empires steadily declined across the first fourteen centuries A.D. The lucky latitudes had become the graveyard of empires.

  Figure 3.7. Order out of chaos: the dark line shows the falling average size of empires in the Eurasian lucky latitudes, A.D. 1–1400 (calculated by the Tukey, or median-to-median, method; ŷ = 3.83 – .047x).

  Second, Toynbee would surely have seen that the wild swings in the size of states are not simply Odtaa: they came in a repetitive boom-and-bust pattern. Counterproductive wars that drove empire size down were followed by productive wars driving it back up, only for counterproductive war to return and break Leviathan down again. Rather than Odtaa, the lucky latitudes were trapped in a terrible cycle.

  The explanation is not hard to find. Because productive war had overshot its culminating point, the steppes and the agrarian empires had become tied together. Every action now had an equal and opposite reaction. At one moment, plagues, rebellions, and invasions would bring an empire crashing down in counterproductive war, leaving millions dead; at the next, local warlords—or perhaps an invader—would wage new productive wars, exploiting the vacuum to bring forth another Leviathan. Its king, enthroned in pomp and circumstance, would struggle mightily to bring back the rule of law and squeeze taxes out of his subjects, only for the wealth of the new state to draw in more raiders and rebels, setting off a new downward spiral of counterproductive war … and so on.

  Each region in the lucky latitudes flipped back and forth between productive and counterproductive war on its own schedule, mostly because one kingdom’s success in driving off raiders tended to increase the pressure on neighboring kingdoms. Some migrations off the steppes were so overwhelming that they seemed to hit everywhere at once, as when Huns plundered all the way from India to Italy in the fifth century and Mongols attacked from Japan to Germany in the thirteenth, but even then the accidents of battlefield victory and defeat randomized the results, producing the apparently chaotic outcomes we see in Figure 3.6.

  There had been counterproductive wars before, but even the worst of these had been breakdowns within a larger pattern of productive war. Some of the collapses had lasted for centuries, but despite the fall of the Akkadian Empire and the Egyptian Old Kingdom around 2200 B.C., the Indus Valley cities around 1900 B.C., and the kingdoms of the eastern Mediterranea
n’s international age around 1200 B.C., Eurasia’s lucky latitudes had kept moving toward Rome, Chang’an, and Pataliputra. For every step backward, there were two or three steps forward.

  Between A.D. 200 and 1400 that ceased to be the case. The power of the steppe horsemen was simply too great. One king or another might thrust back the forces of chaos, but none could permanently stop the steppe migrations. Sooner or later, the roving bandits would be back, and until someone learned how to stop them, Eurasia’s lucky latitudes could not break the bloody cycle of productive and counterproductive wars.

  The Counterrevolution in Military Affairs

  Counterproductive wars threw all the developments described in Chapters 1 and 2 into reverse. Overwhelmed by enemies, governments failed in their basic duty of providing security. Traders stayed home, with disastrous consequences for the kings who taxed them and for the people who needed their goods. With rulers unable to pay their armies, troops made up the shortfall by plundering the peasants, and the peasants sought safety under the protection of great landlords. These worthies organized the increasingly subservient villagers into militias to fight off invaders and tax collectors and generally saw little reason to pay anything to distant monarchs.

  The productive wars of the last five millennia B.C. had driven a string of revolutions in military affairs that converted disorganized rabbles into disciplined, well-led legions, but counterproductive wars now set off what we can only call a counterrevolution in military affairs. Kings, generals, and foot soldiers did not forget the advantages of mass, discipline, and regular meals—after all, what has once been invented cannot simply be uninvented—but as Eurasia’s Leviathans lost their teeth, governments stopped being able to pay for these fine things.

  Armies shrank, navies rotted, supply chains broke down, and command and control collapsed. Back in the eighth century B.C., Tiglath-Pileser III of Assyria had made his mark by cutting the aristocracy out of war, raising (and paying) armies loyal to him alone. A thousand years on, kings started doing exactly the opposite. Unable to squeeze the money for armies out of their wayward barons, they instead started cutting deals with them.

  In the old days, kings and landlords had both taken bites from the meager incomes of their peasants, with monarchs calling their share taxes and local bosses calling theirs rent. Finding themselves too weak to collect taxes, kings now gave up their claims and handed out grandiose titles and privileges to every thug with his own armed gang. In return for leaving the aristocracy to run their estates like mini-kingdoms, the crown extracted promises that its earls, counts, and barons would turn up whenever the monarch wanted to go to war, bringing with them troops raised from their own fiefdoms.

  The easiest way for noblemen to find these soldiers was by repeating the kings’ strategy, passing some of their lands and laborers on to lesser knights in return for more promises to show up and fight. These knights, in turn, passed lands and laborers to still lesser personages, and so on, until webs of rights and duties bound together everyone from the king in his castle to the poor peasants who actually did the work.

  For kings slithering down the slopes of counterproductive war, these arrangements had an obvious advantage: the throne no longer had to pay professional soldiers to fight or bureaucrats to raise taxes. However, organizing armies this way also had disadvantages. The first was that kings now had little leverage over their followers, who often cared more about their own fame and glory than about any larger plan, tending to plunge into battle (or to run away) as the mood took them. The most famous of all medieval battles, at Hastings in 1066, turned on just this issue. At the critical moment, the Normans attacking the right wing of King Harold’s Anglo-Saxon army turned tail and ran. Forgetting orders, doctrine, and common sense, Harold’s brothers Leofwyne and Gyrthe plunged down the hill after them, followed by their cheering men. At the foot of the slope the Normans rallied, turned, and cut down their disorganized pursuers. Its cohesion broken, the Anglo-Saxon line now came apart. The kingdom was lost.

  According to legend, King Harold was shot through the eye by a Norman arrow, but even if he had extricated himself from the rout, Harold would have run straight into the second great problem of warfare in this age. Kings who did not win battles did not win plunder either, and despite all the oaths and talk of duty, kings who had no loot to hand out got little loyalty from their men.

  The Norman leader William the Conqueror, on the other hand, could now reward his followers by sharing out England’s broad acres. Yet even he and his heirs soon ran into difficulties, because the new arrangements created a third problem. As generation succeeded generation, the webs of duty and obligation binding a king and his knights grew increasingly tangled. Clever or lucky lords used inheritance, dowry, and purchase to expand their estates, but each new estate brought new obligations. All too soon, a man would find himself owing allegiance to multiple masters.

  Such was the fate of Count Robert II of Flanders. In 1101, Count Robert swore fealty to King Henry I of England, pledging—as was customary—to aid his master “against all men who live and die.” However, Robert added, that did not include the one man King Henry was actually worried about, King Philip of France. Robert could not promise to fight Philip, because he was already Philip’s vassal. Robert assured Henry that if King Philip decided to attack England, he (Robert) would try to talk him (Philip) out of it, but if jaw-j aw failed and Philip went ahead with an invasion, Robert admitted that he would be obliged to fight on the French side—but insisted that he would only send enough troops to avoid looking unfaithful.

  If, on the other hand, King Henry of England wanted Count Robert’s help in a war that was not against France, Robert would gladly provide it—unless (a) Robert was unwell, (b) the king of France asked Robert to fight in a different war, or (c) the German emperor (who was another of Robert’s masters) had also called on Robert. As if this were not complicated enough, Robert’s final promise was that if France invaded Normandy—which would almost certainly mean war between France and England—he would send just 20 of his knights to fight on the French side and the other 980 to fight for the English.

  This impossible mess of crosscutting allegiances was the outcome of centuries of decline. A few pages ago I mentioned the Byzantine emperor Justinian’s attempt to reunite the Mediterranean Basin in the sixth century A.D., but after that failed, Leviathan’s breakdown had begun in earnest. Starting in the 630s, Arabs bringing the new faith of Islam infiltrated out of the desert, overwhelming the tiny armies that the Byzantine Empire could now afford. In the 650s, the Arabs overthrew Persia’s Sasanid rulers, and for the next half century Byzantium looked as if it were about to go the same way.

  By 750, Muslim war parties had triumphed everywhere from Morocco to Pakistan, raiding deep into France and putting Constantinople under siege, but the caliphs never managed to put their Leviathan on a very firm footing. From the earliest days of Islam, caliphs had held an ambiguous position, somewhere between a divinely inspired successor to Muhammad and a conventional king. None really succeeded in converting religious authority into secular rule over more than a small part of his vast empire. By the ninth century many local sultans were effectively independent rulers, fighting each other, the caliph, and anyone else who came along.

  Far to the northwest, the Germans who had overrun the western Roman Empire built up new kingdoms, which waged productive war when they had strong kings and counterproductive war when they did not. The most productive of their rulers was the Frankish king Charlemagne, who conquered much of western and central Europe between 771 and 814. Bureaucrats in the wooden halls of his capital at Aachen bullied local lords, squeezed taxes out of them, promoted literacy, and desperately tried to impose order on the king’s subjects. In 800, a thoroughly cowed pope even put a crown on Charlemagne’s head and proclaimed him Holy Roman emperor, but the dream of a revived Roman Empire quickly died. The immediate cause was that Charlemagne’s son and grandsons got far too busy fighting each other to spare
much time for keeping unruly aristocrats in line. “This caused great wars,” a contemporary chronicler lamented, “not because the Franks were lacking princes who were noble, strong, and wise enough to rule their kingdoms, but because they were so equally matched in their generosity, dignity, and power that the discord increased, because no one excelled so much above the others that they would submit to his lordship.”

  Even before Charlemagne died, however, new raiders—Vikings coming from the north in longboats and Magyars coming from the east on horseback—had begun plundering the wealth that his productive wars had generated. Aachen was simply too far from the frontiers to respond to these hit-and-run attacks, and in a familiar story local lords stepped in to fill the security void. Not even the great Charlemagne could have held the forces of counterproductive war in check. By 885, when the much-iess-great emperor Charles the Fat conspicuously failed to show up at Paris while Count Odo held off a Viking siege, the empire was effectively a dead letter.

  It was every man for himself in this messy new world. The first reference in our sources to a man serving multiple masters in fact comes just a decade after Odo’s defense of Paris, but across the centuries that followed, it just got more and more common. By the 1380s, five hundred years after Odo, the problem had become so bad that a French cleric proposed a one-size-fits-all solution. The overcommitted warrior, he recommended, should fight for the first lord to whom he had sworn an oath while discharging his obligations to his second (and third, and fourth, and so on) lord by hiring substitutes to fight instead.