4

CLASH

ON THE MORNING OF OCTOBER 1, 331 B.C., on a broad and treeless plain beneath the Zagros Mountains in what is today Iraqi Kurdistan, the cavalry charged. Once the trumpet sounded, thousands of horsemen from out of the Eurasian steppe, all heavily armed—some to the point that even their horses wore armor—came hurtling out of the Persian lines. They aimed at outflanking and outfighting the Macedonians and driving the enemy’s lines into chaos. It was the start of Gaugamela, the greatest battle that Alexander and Darius would ever fight.

A little more than a century later and three thousand miles to the west, on an August morning in 216 B.C., the harsh and mournful sound of the Celtic war horn rang out in the valley of the Aufidus River in southern Italy. The Celts were fighting for a large Carthaginian army that was about to clash with an even more massive Roman force. The Carthaginian cavalry charged up a lane between the river and the left flank of the Roman infantry. The Celts attacked with a hail of javelins, followed by lances and long swords. Alongside them rode squadrons of Spanish cavalry armed with spears and falcatas, curved swords with a deadly eighteen-inch blade. The sixty-five hundred Celts and Spaniards outnumbered the twenty-four hundred Roman horsemen by more than two to one. In the narrow space between the river and the Roman infantry, there was no room to maneuver, so the cavalrymen on both sides dismounted and fought on foot. It was an old-fashioned, blood-and-guts, hand-to-hand fight. The worst day in the history of the Roman army—the battle of Cannae—had begun.

A little more than 150 years later and three hundred miles to the east, on a hot, steamy summer day in 48 B.C., six thousand cavalrymen advanced across the central Greek plain to the rumble of the commander’s horn and the cry of the trumpet. Well armed, well fed, well led, they were the sons of aristocrats and kings, making up a mosaic of nationalities from Gaul to Italy to Greece. Wearing chain-mail armor or tunics, plumed helmets or felt caps, brandishing javelins and lances, long swords and scimitars, they galloped over the gap separating them from their enemy. Only a thousand cavalrymen, most of them Gauls and Germans, rode on the other side. The attackers planned to roll them up, charge into the flank of the enemy’s infantry, and plunge his army into chaos. In spite of the international cast of cavalrymen, this was a Roman conflict. It was the great civil war between Caesar and Pompey and its bloodiest battle—the battle of Pharsalus—was under way.

Three great battles, three dramatic charges: Hollywood couldn’t have done it better. But screenwriters have it easier than conquerors. They don’t have to argue with their audience in order to write a climax into the script; the audience demands it. Moviegoers love a crisis; military strategists are less predictable. Having overcome initial setbacks, each of our three great commanders now wanted to force a decision via pitched battle, but he had to get the enemy to oblige. If the enemy respects the conqueror’s reputation as a giant of the battlefield, the enemy might prefer an indirect strategy such as a war of attrition or a counteroffensive in another theater.

Bringing their opponents to the battlefield, then, was a challenge for Alexander, Hannibal, and Caesar alike. After Issus, Alexander hoped that Darius would agree to a rematch, but Alexander had no way to know what Darius was thinking. After Fabius’s strategy, Hannibal adjusted his plans to try to lure the Romans back into battle, but the decision was up to them. After Dyrracchium, Caesar hoped to breathe life back into his army and tempt Pompey into fighting a pitched battle, but Pompey resisted—at first.

In the end, the enemy obliged, and the three generals each got the battle they had hoped for. The result was each man’s finest hour. At Gaugamela (331), Cannae (216), and Pharsalus (48), Alexander, Hannibal, and Caesar respectively won three of the great pitched battles of military history. Here, we examine how they did it. What they made of the results is a subject for the next chapter.

GAUGAMELA

From Egypt to Babylon was about 750 miles by the caravan routes through Syria. It was just off this historic road, on the hot and dusty Assyrian plain, south of the foothills of the Zagros Mountains, that the armies of Macedon and Persia met for their greatest battle.

Eclipse

October 1, 331 B.C., was a day of destiny. Even Babylon’s famous astrologers took note. They recorded a battle that morning in which an invading army inflicted a heavy defeat on the great king’s troops. The stars, they say, had predicted it. A week and a half earlier, on September 20, a lunar eclipse—at nighttime, with Saturn present, Jupiter absent, and a west wind blowing—foretold ruin for the king at the hands of an intruder from the west. And so it happened at the battle of Gaugamela (pronounced “gaw-guh-MEE-lah”) on October 1, when Alexander defeated the last army that Darius would ever raise against him.

Alexander was eager for this battle. He hoped to beat Darius again, and to finish what he had started at Issus, making Alexander in fact what he already claimed to be: the king of Asia. But Darius was eager to fight as well, and the question is why. Wouldn’t Darius have been better off by avoiding battle?

Darius might have followed a scorched-earth policy instead, which would have worked simply: deny food to Alexander’s army as it marched eastward. Meanwhile, Persian cavalry units could attack in sudden, unpredictable, hit-and-run raids, especially dangerous if the Macedonians split up in small groups to look for supplies. Bleeding, hungry, and off balance from Persian attacks, the army might force Alexander to turn back. True, he would still control Darius’s lost provinces west of the Euphrates, but Darius would hold the east.

But this strategy too was risky. Many towns might prefer opening their storehouses to Alexander rather than go hungry for Darius. In the end, they could very well decide that one king was as good as another. Darius, therefore, had his reasons to choose to fight another battle. If anyone could make the third time a charm, it was he.

He had spent the eighteen months since Issus wisely: he showed good judgment by building a new army. Unlike his earlier armies, it was almost entirely a cavalry force—and an excellent one. Despite Alexander’s victories, Darius still controlled a gigantic empire, and it held untapped resources. Then as later, Central Asia was famous for its horsemen, and Darius assembled a superb group.

They came thundering out of the vast Eurasian steppe. Descendants of nomads, they were renowned for horse breeding and cavalry tactics. Darius’s best cavalry were the riders of Bactria and Sogdiana (modern Afghanistan, Tajikistan, and Uzbekistan), supplemented by cavalry from western India and by the knights of the Saca peoples (who lived north of Sogdiana, in the eastern tip of modern Uzbekistan). The Saca were so heavily armed that even their horses wore armor, but the horses of Central Asia were and are known for great stamina.

They had weapons as good as the Macedonian army and better armor. Some had a well-deserved reputation as archers. Others received Macedonian-style pikes, long swords, and shields. Darius provided them, because he had learned the hard way just how effective they were.

These magnificent, terrifying, and deadly horsemen also enjoyed an excellent commander in Bessus. A prominent nobleman, Bessus was satrap of Bactria and Darius’s relative. He molded an elite force that could stand comparison with Alexander’s Companion Cavalry.

Darius’s problem was infantry. A state-of-the-art military in 331 B.C. required a balanced mix of cavalry and infantry. Alexander’s heavy infantry, for example, protected his cavalry from a frontal attack while adding weight to the cavalry’s offensive punch. At Gaugamela, Alexander had about forty thousand infantrymen. But Darius had to do without effective infantry: Alexander had cut off the supply of Greek mercenaries, the traditional source of Persia’s heavy infantry. Darius would have to make do with the two thousand Greek mercenaries he had left and two thousand elite Persian infantrymen, who were no match for Alexander’s numbers.

To slow down Alexander’s deadly cavalry charge, Darius had two other hopes: elephants and scythed chariots. Neither was very promising. Darius had fifteen elephants at Gaugamela. They could have protected him from an attack by Alexander’s cavalry, but Darius’s own troops probably lacked the training necessary to handle the beasts, and the elephants likely stayed in camp. Then there were Darius’s scythed chariots. These fierce-looking machines bristled on either side with spikes, spearheads, sword blades, and scythes. Yet past experience showed that disciplined units of soldiers could parry any threat from them.

It came down to Darius’s cavalry. So he gave them an edge in numbers. Alexander had seven thousand cavalrymen. Darius’s cavalry numbers are unknown, but they greatly outnumbered Alexander’s, probably by at least three to one if not more: twenty-five thousand Persian cavalrymen is an educated guess.

Finally, Darius carefully chose a suitable battlefield and did everything he could to lure the enemy to fight there. He picked a wide-open plain, with few or no shrubs or bushes, and had his engineers flatten the few low hills: now his chariots and cavalry would have the space to maneuver that had been lacking at Issus. He chose Assyria (Iraqi Kurdistan) as the place to make his stand. The region offered plains and plenty of food and it stood on Alexander’s likely marching route south and east: to Babylon (near modern Baghdad), now Darius’s western capital, and to Persia beyond it.

Darius gave his cavalry the tools to carry out a double envelopment of the enemy. They would surround Alexander’s army on both sides and overwhelm it. That was the plan: the question was, how well could the Persians execute it? And could Alexander make a set of countermoves to stop it?

For his part, the Macedonian King fielded the largest army he had ever commanded. They were veteran forces and they enjoyed the morale boost of past victories.

In early spring 331, Alexander and his men headed northeast from Egypt. After stopping at Tyre, they marched inland. Around August 1 a Persian regiment watched the Macedonians cross the Euphrates River at Thapascus (today, in north-central Syria) but it did nothing to stop them. Indeed, it looks as if the Persians were pointing Alexander toward Darius, who was waiting about three hundred miles to the east in Assyria with his army. As Alexander marched eastward, Persian scouts, captured by the Macedonians, gave the false news that Darius planned to block Alexander from crossing the Tigris. Alexander hurried to the Tigris but found no one there. The river was fordable but just barely; a rough current tired out Alexander’s men by the time they reached the other shore. Still, the Persians did nothing to oppose them other than burning crops to deny the enemy food. It was mid-September.

Roughly seventy-five miles away, the Persians were waiting on Darius’s chosen battlefield. They were probably somewhere between the Gomel River and the Jabal Maqlub Hills, which rise three thousand feet above the plain: either north of the hills, near the small town of Tell Gomel, or south of the hills, near the city of Qaraqosh (modern Al Hamdaniya). In either case, the terrain was similar, a large expense of fairly flat land among eroded hills.

After crossing the Tigris, Alexander rested his army for two days. Then, on the night of September 20, came the eclipse. Alexander had planned to start the march again the next morning, but his men were too frightened. Instead, he sacrificed animals and called in a soothsayer to reassure the troops that this was an ill omen for the Persians, not them. As a good leader, Alexander attended to his men’s mood.

And yet, the coming days reawakened their fears. Nine days of marching and resting brought the Macedonians to the Jabal Maqlub, from whose heights they could see Darius’s army clearly, about three and a half miles away, filling the plain in its battle order. That huge force gave Alexander and his senior commanders enough pause that he delayed the battle for a day.

Defense with a Sting

Alexander rode around the entire battlefield the next day on a scouting mission with his light-armed troops and Companion Cavalry. He then put his mind to work on refining his battle tactics. Not that he planned to change a winning formula. Alexander left the heart of the Macedonian battle order in place, but he needed to protect it from the danger of being outflanked by Darius’s big and powerful cavalry. Masterful tactician that he was, Alexander figured out Darius’s plans and came up with a way to counter them.

The Persian line stretched for several miles across the plain. Darius held the great king’s traditional position in the center, guarded by his elite Persian infantry and Greek mercenaries. Fifty scythed chariots and fifteen elephants (which would not take part in the actual battle) were posted in front of him. The right wing, commanded by Mazaeus, former satrap of Syria, was made up of cavalry from Syria, Mesopotamia (Iraq), and parts of Iran—which produced excellent horsemen. Mazaeus also had fifty scythed chariots. The left wing, commanded by Bessus, satrap of Bactria, contained the great cavalry contingents of the east as well as one hundred scythed chariots. This wing was Persia’s stronger arm, and it would face Alexander’s best troops on his right wing. The bulk of Persia’s infantry stood in the rear, which was appropriate, since they were too weak to play much of a role in battle.

As Alexander could see, his opponent had a bigger army than at Issus, rich in cavalry but poor in infantry. Alexander understood that, in strategic terms, Darius stood on the defensive; he had challenged the enemy to come to him. In tactical terms, though, Darius needed to go on the offensive: Darius had to attack first.

Cavalry was the Persian’s strong suit. Fresh and motivated at the start of battle, his horsemen might overwhelm the enemy. But if Darius let Alexander attack first, he risked cracks in his shiny military machine—if not worse. Darius had enough heavy infantry to absorb a frontal attack by Alexander but not enough to turn around and go on the counteroffensive.

Darius’s superiority in numbers allowed him to outflank Alexander on either side. His best move in battle was to envelop Alexander’s two wings with his powerful cavalry. If they did their job well, they would leave the rest of the Macedonian army defenseless—and certainly unable to attack. Alexander had to come up with a plan that would parry the Persians’ cavalry strike and allow him to counterattack in turn. He also had to protect his flanks without thinning out his line to the point where it left his center weak. His solution was a novel, flexible formation.

At first glance, Alexander arranged his army in a familiar pattern. The Macedonian infantry phalanx took its usual position in the center, linked to the Companion Cavalry on their right by the hypaspists, the elite corps that made sure no gap opened up in the line. On the left stood two sets of cavalry units—those of the Thessalians and those of the other Greek allies. As usual, Alexander took command of the right wing of his army and put Parmenio in charge of the left.

What made this army different, however, was a series of additional formations that created what was more or less a rectangle. The sides of the rectangle were made up of a flank guard on each wing. Each of these two flank guards was thrown back at about a forty-five-degree angle from the front line. Each flank guard was made up of several infantry units, arranged like a set of steps, and guarded by a screen of cavalry. Finally, the back of the rectangle was made up of a second set of infantry, positioned behind the front line and parallel to it. Their job was to turn and meet the threat from the rear—the Persian horsemen might ride all the way around the rectangle.

It was on the sides of the rectangle, though, and not the rear, that Alexander planned to fight. He wanted to draw the Persian cavalry into a fight with the flank guards on his army’s two wings. Those guards’ mix of cavalry and infantry represented defense with a sting. Hidden behind their own horsemen, the infantry would emerge during the battle and dash into action. Light-armed troops, including archers and javelin-men, they offered a quick and deadly counterweight to the Persian’s superiority in cavalry numbers—especially on Alexander’s right wing, where he was stationed and where he put his best troops.

Alexander predicted that the charge of the Persian cavalry on either wing would leave a gap in the enemy’s line. He planned to rip right through that gap by a combined charge of his elite Companion Cavalry and the Macedonian phalanx. Meanwhile, however, his weaker wing, the left wing under Parmenio, would bend under a Persian onslaught. Alexander knew that he might find himself in a race against time, hurrying to win on his right and then turning to help Parmenio before the Persians overwhelmed him.

In short, Alexander displayed his extraordinary judgment as a commander. He took his superb, combined-arms force and—on the spot—made it better. He displayed agility as well as insight. Above all, it was an exercise in audacity.

Having figured out his battle plan, Alexander called a conference of his top officers. He told them that they were fighting not for a province or a country but for the control of all “Asia”—that is, for the Persian empire. He emphasized the importance of strict discipline; of keeping silent on the advance but marking the charge with shouts and battle cries. Then, ever the good leader, he attended to morale by giving the men a meal and a good night’s sleep. He himself rested as well, but not before he sacrificed to the god Fear, according to one source.

Darius, for his part, feared a Macedonian nighttime attack, so he kept his men at their posts all night long. Not knowing when or where the enemy might attack, he couldn’t rely on just a small force of guards to protect the army. The Persians faced the morning fatigued, which hardly helped them in battle.

At dawn, Alexander appeared in his best armor and rode up and down the ranks. He held his lance in his left hand, raised his right hand, and called on the gods. In Anatolia and Egypt, oracles had proclaimed him to be the son of Zeus. Alexander did nothing to discourage the idea, as it strengthened his brand. Some Greeks had already hailed previous conquerors as demigods, and Alexander had outdone them.

As he rode along the ranks, Alexander asked the gods, if he really was the son of Zeus, to guard and help strengthen the Greeks. As if on cue, an eagle supposedly appeared above Alexander and flew straight toward the Persians.

The battle was about to begin.

The Eagle Pounces

Gaugamela is hard to reconstruct. The battle lines stretched for miles, so no one man was in a position to see the whole thing. The flat and featureless landscape offered no landmarks to aid memory. Both sides engaged in complex tactics. Each side’s cavalry charges raised clouds of dust. Even with perfect sources, the battle would be a challenge to describe, and our sources are flawed.

Alexander began the battle by marching toward the right, moving at an oblique angle to the Persian front. As he drew near the end of the Persian line, Darius began to worry that Alexander would move off the ground that had been smoothed for his scythed chariots. So he sent the Bactrian and Saca cavalry under Bessus to ride around Alexander’s right and stop his march.

The trumpets and battle cries sounded. Alexander, in turn, ordered the leading edge of his right flank guard to charge—just a small squadron, which the Persians easily pushed back, but it served as bait. The rest of Bessus’s cavalry now joined in, a terrifying sight as they charged. But the fight was developing exactly where Alexander wanted it, on his right flank guard. His defense with a sting was up to the challenge. He did not destroy Bessus’s cavalry but he stopped it.

Meanwhile, Darius ordered his scythed chariots to plow into the enemy. But the Macedonians were prepared. On the Macedonian right and center, a screen of archers and javelin-men fired; in some cases they actually grabbed the reins and pulled down the drivers. Some chariots got through, but the men had been trained to part ranks and let them pass. The chariots accomplished little or nothing, at least on the Macedonian right. Perhaps they did more damage on the Macedonians’ weaker, left wing, where another Persian cavalry charge, led by Mazaeus, hammered Parmenio’s Thessalian cavalry.

Around this time a gap appeared in the Persian line, between the left and the center, caused by the departure of Bessus’s horsemen. Alexander seized the moment. He formed his elite Companion Cavalry into a wedge, ordered the Macedonian phalanx to advance beside them, raised the battle cry, and charged. They cut through the opening in the enemy line and ripped apart his exposed flank. The sources describe the scene vividly: “For a short time the battle became a hand-to-hand fight. The cavalrymen around Alexander and Alexander himself pressed the enemy hard and robustly, shoving and using their lances against their faces. They pounded the Persians, and the Macedonian phalanx, thickly massed and bristling with pikes, struck them as well.”

As at Issus, Darius was the target. Kill or capture the king and win the war: that was Alexander’s plan. It would have worked too, thanks to his men’s unstoppable advance, but Darius turned and fled. He was no coward; he hoped to fight again another day.

Besides, the battle wasn’t over, and for a while, it looked as though events elsewhere on the field might give Darius his chance. Just as Bessus’s charge opened a gap in the Persian line, so Alexander’s charge left one or more holes in the Macedonian center and left. Now, Persian and Indian cavalry poured through them. They had a golden opportunity to join Mazaeus’s fight against Parmenio’s already struggling troops.

Parmenio, meanwhile, sent a message to Alexander asking for help, but the message probably never reached him. The battlefield was chaos, and in all likelihood, Alexander had already taken off in pursuit of Darius. Darius’s flight filled “the air . . . with the groans of the fallen, the hoofbeats of the horses, and the constant noise of the whips,” according to one source. It also raised a thick cloud of dust that hampered the Macedonians’ pursuit. Alexander turned back toward his left wing.

If Alexander had gambled on Parmenio muddling through, he was correct. The old man had a history of hanging on in a tough fight, and his Thessalians were intrepid. Meanwhile, instead of helping Mazaeus against the Macedonian left, the Persian and Indian horsemen plundered Alexander’s camp far behind the lines. They wasted their opportunity to aid Mazaeus, only to be driven back by Macedonian infantry in the rear.

In any case, once the Persian cavalry learned about Darius’s flight from the field, they halted the struggle. Not that they were broken: as they rode off, they ran smack into Alexander’s Companion Cavalry, who were finally heading toward Parmenio. The result was the most hard-fought cavalry encounter of the day. There was none of the usual spear throwing or turning movements that were the rule in cavalry fights. This was a brawl, with every man trying to break through and save his life. Sixty of Alexander’s Companions fell, and three senior officers were wounded, including Hephaestion, Alexander’s closest friend.

It did nothing to change the outcome of the battle. Alexander had delivered Darius a decisive defeat. The Persian did not fail from want of trying. He maneuvered the enemy onto his chosen battlefield, where he forced him to face an overwhelming array of power on horseback. But the Macedonians brought the most versatile army in the ancient world to the field, at the height of its self-confidence and experience. They had outstanding commanders: Parmenio, for example, was an unsung hero for absorbing the enemy’s battering and holding the Macedonian left together. They had a marked advantage in infrastructure.

But the main difference between the two armies—the decisive advantage—was Alexander’s superiority as a general. Both in preparation for the battle and in the heat of combat, Alexander showed himself to be Darius’s master. Displaying strategic intuition, he scrutinized the enemy’s battle order with an expert eye and rearranged his tactics handily. He kept his cool in the heat of battle and aimed the decisive blow at the right place and time. True, not everything went according to plan: Darius escaped, the Macedonian line was broken, and casualties were not small. But the result crowned Alexander’s achievements. Darius was a good general but Alexander was a military genius.

There are no accurate casualty figures for the battle. The sources probably minimize Alexander’s losses and inflate Darius’s: their estimates range from 100 to 500 Macedonian dead, and from a sky-high 40,000 to a silly 300,000 Persian dead. Although Gaugamela saw ferocious fighting, many Persians escaped, some of them in units that maintained good order. Persian casualties were not light but they were not huge either.

Gaugamela was Alexander’s greatest battlefield victory. It marked the end of pitched battle against the Persian empire. Mesopotamia and, for that matter, Iran too now lay at his feet.

Darius fled first to the nearest city, Arbela (modern Irbil), about sixty miles to the southeast. He then headed into the mountains of western Iran, with the remnants of his royal guard and his mercenaries, as well as Bessus’s cavalry, which had survived in good order. Mazaeus and his surviving men fled to Babylon.

Alexander too went to Arbela after the battle. There, his men acclaimed him as “king of Asia.” Alexander had first claimed that title in a letter to Darius after the battle of Issus. Now, it seemed no mere claim: it was real. At Arbela he also took the diadem—a ceremonial cloth headband—as his royal insignia. Three weeks later, after hammering out a settlement with Mazaeus, Alexander entered Babylon, where he was again acclaimed as king, this time officially.

But the war was not over. Darius still controlled Iran and Central Asia. Not only did Alexander have to catch him, he had to win his surrender to Alexander’s new royal title as king of Asia. And he wanted to get Darius to bring the remaining Persian elite along with him. Otherwise, Alexander would have to conquer another million square miles of territory the hard way, hill and valley by bloody hill and valley. Either that, or he would have to accept that the “king of Asia” did not control eastern Iran or the provinces beyond it.

Nor could Alexander count on the support of his army. As far as many of his commanders and men were concerned, the war was all but over—only the capture of Persia’s royal capital was left. They had no interest in the remote east. They wanted only as much of Persia’s former empire as they could govern from Macedon.

Alexander would have to solve these problems if he was to enjoy the fruits of his victory at Gaugamela.

CANNAE

The “table land,” or Tavoliere, is a sweeping plain, rich in farmland, and stretching across twelve hundred square miles in Apulia (Puglia) in southeastern Italy. Once, in prehistoric times, it was part of the ocean, but the land was dry as dust when, on a summer day in 216, Hannibal and the Romans met on the region’s southern edge, at Cannae.

The Greatest Land Battle

August 2, 216 B.C., the day of the battle of Cannae, was one of the most terrible days in human history. Nearly as many men died on that August day at Cannae as on an August day in Hiroshima, two thousand years later—and without gunpowder, let alone an atomic bomb. (Hiroshima’s casualties rose much higher over time because of radiation sickness.) Swords, spears, sling stones, horses’ hoofs, the weight of thousands of marching feet on the fallen, heatstroke, exhaustion, terror, and even despair: these were death’s tools at Cannae.

Cannae was to Hannibal what the lever was to Archimedes. The Romans outnumbered Hannibal at Cannae by nearly two to one and they got to fight the battle when and where they wanted. And yet Hannibal annihilated them.

Hannibal, the victor, killed about 48,000 Romans and took about 20,000 prisoners; only about 15,000 Romans escaped. The Romans killed between 6,000 and 8,000 of Hannibal’s approximately 50,000 men. The Romans lost about 75 percent of their army: a little more than half of the Roman army was killed and another fourth was captured. The Carthaginians lost about 10 to 15 percent of their army. It was one of the most lopsided victories of all time.

Skeptics then and now have downplayed Hannibal’s genius. They argue that he didn’t win the battle, but rather, the Romans lost it. There is some truth in this. Without Roman errors, Cannae would have been a Roman defeat but not a disaster. Yet without Hannibal’s brilliance, Cannae might have been a Roman victory.

How did this explosive battle come about? Both the Romans and Hannibal wanted it. Hannibal was confident of his ability to win yet again, as he had done at the Ticinus, the Trebia, and Lake Trasimene. Incited by Hannibal’s provocation, the Romans threw out Fabius’s policy of avoiding battle. In 217 B.C. Hannibal teased like a wily matador, and his tricks drove an angry Roman bull to the point where it could no longer resist battle.

The new consuls of 216 B.C., Gaius Terentius Varro and Lucius Aemilius Paullus, broke with Fabius’s policy; they would fight. And they would do so with a massive, sledgehammer force, the largest army the Romans had ever raised, and the first one to be commanded by both consuls; usually, they led separate armies. Although they were inexperienced, they expected to win through sheer force of numbers. They wanted a war-winning move.

But that was in August. Earlier that spring and summer, another, smaller Roman army had shadowed Hannibal.

He made the Romans chase him. He drew them down from the hills around Luceria (modern Lucera), in northern Apulia, to the plain near the sea at Cannae. Ironically, the greatest land battle in the ancient world took place practically at the edge of the sea. Cannae lies about five miles, as the crow flies, from the modern coastline. From the hill of Cannae, Hannibal would have been able to see the blue Adriatic clearly. He could have felt the sea breeze or watched the swallows diving gracefully in the sky.

He might also have thought about the blow that he had already struck by seizing the citadel of Cannae. Rome had established a supply dump there, and its grain and other provisions now belonged to the Carthaginians. More important, Cannae had a strategic location.

Apulia is cavalry country, and so was perfect for Hannibal. About ten miles away from Cannae lay the important Roman ally of Canusium, the fields of which city Hannibal’s men now raided.

Cannae sits in the valley of the Aufidus (modern Ofanto) River, which flows from the far side of the Apennine all the way to the Adriatic Sea. The Aufidus Valley offers access across the Italian peninsula to the strategically important Bay of Naples, on Italy’s west coast. By seizing Cannae, Hannibal endangered one Roman ally (Canusium) and threatened to open the road against others. Rome had to respond. And so, Varro and Paullus brought their troops to Cannae. After joining up with the smaller Roman army already in Apulia, the Romans had about 86,000 fighting men. Hannibal had approximately 50,000.

In its last stretch, in the area around Cannae, the Aufidus River sweeps between two ranges of hills and then, northeast of the citadel of Cannae, the hills drop away, the valley opens up, and there is a broad, slightly sloping plain that would have served well for the battle. Most historians locate the battlefield there, although a case can also be made for a site in the hollow between the hills.

Before the day of battle, the two sides maneuvered. When they reached the vicinity of Cannae, the Romans probably camped on the left bank (north side) of the river Aufidus. Hannibal was camped on the right bank, at the foot of the citadel of Cannae. The Romans threatened Hannibal with a small camp on his side of the river, and then Hannibal responded by moving his camp across the river to the Roman side on the left bank. On August 1, Hannibal challenged the Romans to fight but they refused. Then, the next day, the Romans crossed the river again and took up Hannibal’s challenge.

What explains this elaborate game of chicken? One possible explanation is the Roman system of command, by which the two consuls alternated the supreme command daily. The ancient sources say that Paullus, who commanded on August 1, had decided not to risk a pitched battle against Hannibal, but Varro took command on August 2—and took the plunge. More likely, the Romans wanted to fight on the right bank, where the terrain was slightly less favorable to cavalry. Parts of it lay on a gentle gradient and parts offered less room to maneuver than on the left bank.

In either case, shortly before dawn on August 2—that is, shortly before 4:30 A.M. (daylight time)—Varro raised the red flag outside his tent, the traditional Roman signal for battle. Despite claims of tension in the sources, the other consul, Paullus, is likely to have cooperated fully. Rome had sent out its legions and they had found the enemy. The day of glory had arrived. Immediately after sunrise—6:00 A.M. (daylight time), Varro began leading the men out of both camps. He led the troops from the main camp across the River Aufidus to the right bank, where the troops from the smaller Roman camp joined them. Hannibal climbed a low hill and watched the Romans arrange for battle, as his own forces prepared.

The Romans left ten thousand men behind to garrison the main Roman camp and to threaten the Carthaginian camp, thereby forcing Hannibal to subtract guard troops from his already smaller numbers. So 76,000 troops took the field for Rome: 70,000 infantry and 6,000 cavalry. Of those 70,000, an estimated 50,000 were heavy infantry while 20,000 were light armed. Of the cavalry, an estimated 2,400 were Roman citizens and 3,600 Italian allies of Rome.

To turn to the other side, Hannibal brought 50,000 fighting men to Cannae: 40,000 infantrymen and 10,000 cavalrymen. The estimated breakdown of those numbers is as follows: the 10,000 cavalrymen consisted of 2,000 Spaniards, 4,000 Celts, and 4,000 Numidians. The 40,000 infantry consisted of 32,000 heavy armed and 8,000 light armed troops. The heavy infantry comprised 8,000 Libyans, 4,000 to 6,000 Spaniards, and 18,000 to 20,000 Celts.

Each side had been at Cannae long enough to reconnoiter the ground and make its plans for battle. Each side fought according to its way of war. Brutal simplicity marked the Roman plan. Hannibal’s army moved with the cunning of a wrestler who, with a feigned glance or a misleading hand movement, tricks his opponent into mistaking the true direction of his attack.

The Romans drew up their infantry in a conventional parallel formation. The Roman army faced south, with the Roman heavy cavalry anchored next to the river, on the right wing; allied heavy cavalry held the left wing. The infantry was placed in the center, drawn up in a conventional parallel formation, but with one important and unusual detail. The Romans grouped the companies (maniples) tightly together, to make an infantry formation that was especially deep and narrow. The result was to create a virtual human battering ram, aimed at the center of Hannibal’s line.

The condensed order of the troops also spoke to the Roman soldiers’ inexperience. Because the Romans had raised such a huge army, much of it consisted of raw recruits. Perhaps the only way to keep order on the battlefield was to bunch them close together. The more experienced men were grouped in the center, providing a solid core, while the less experienced soldiers stood on the wings. The consul Varro commanded the left wing while the other consul, Paullus, commanded the right; the two ex-consuls of the previous year commanded the center.

The Roman infantry at Cannae was drawn up to a depth of between fifty and seventy-five ranks. The width of the infantry was about one to one and one-fourth miles, with the cavalry covering about another half mile, for a total of about one and one-half to one and three-fourths miles. Hannibal had far fewer men, but he had to cover the same frontage or risk having the enemy attack his flanks.

The Roman generals were still thinking about the previous battle instead of focusing on new conditions, as they should have. They knew what had worked at the Trebia and they wanted to try it again but to do it better. That is, they had broken through the Carthaginian center with their infantry at the Trebia, so they decided to stake everything at Cannae on breaking through the center with their infantry again. Against an ordinary opponent, that might have worked.

But Hannibal had not let his understanding of tactics stand still. Unlike the Romans, he had learned something from history. At the Trebia, Hannibal had been willing to sacrifice his center in order to win on the wings. At Cannae, he would also sacrifice his center but not to win on the wings. Instead, he held his wings in reserve and then had them turn inward to strike the advancing Romans on their flanks. It was a complicated and risky maneuver that only a professional army with veteran soldiers and a solid network of subordinate officers could carry out.

Unlike the Romans, Hannibal worked almost entirely with veterans. No new Africans or Spaniards had joined his army since the start of the war; only the Celts could have provided new recruits, as they probably did.

At Cannae, Hannibal came up with a brilliant variation of past tactics. He organized his center in a crescent, billowing out toward the enemy. He manned the center with infantrymen, Spaniards and the Celts. They made, Polybius says, “a strange and terrifying appearance,” brandishing great swords and drawn up in alternate companies, the Celts bare-chested and the Spaniards wearing short, purple-bordered linen tunics. But they were not Hannibal’s best troops—that honor went to the Libyans, who stood on the two wings. Experienced, loyal, and hard as stone, the Libyans also had the advantage of bearing state-of-the-art arms and armor, selected from among the loot from the fifty thousand Roman troops killed or captured since Hannibal had crossed the Alps.

The cavalry played a crucial role in Hannibal’s plan. His heavy cavalry, who were Spaniards and Celts, stood on his left flank, near the river and opposite the Roman cavalry. His light cavalry, the Numidians, held his right flank. Hannibal and his brother Mago commanded the infantry center. Hasdrubal (not Hannibal’s brother) commanded the heavy cavalry on the left, while Hanno led the light cavalry on the right. Maharbal commanded a reserve force of cavalry. Hannibal’s army faced north.

Bloody Morning

Probably around 9:00 or 10:00 A.M., the battle began. Ancient battles usually started with skirmishing by the light troops, and Cannae was no exception. The experienced Carthaginian slingers and javelin-men got the better of the Romans. Then, the survivors on either side withdrew into the ranks of the infantrymen, leaving a stunning sight: about 100,000 men on foot or horseback, poised to fight to the death. The most massive army of citizen-soldiers that the world had ever seen was about to march into one of antiquity’s two or three best professional armies. In the summer, the Apulian plain is hot and dry, and the marching of the men no doubt stirred up an enormous cloud of dust.

The cavalry clashed first. Hasdrubal’s heavy cavalry on the Carthaginian left wing charged the Roman cavalry. Cavalry battles in this period usually consisted of a series of charges and pursuits, with reserves pouring in to allow each side to re-form and charge again, until finally the loser turned and fled. Not Cannae. Hemmed into a narrow space beside the river, the Roman cavalry tried to hold its ground, but the Carthaginians were more numerous, more experienced, better trained, and more confident. Many of the Roman horsemen dismounted and tried to fight on foot. It was a desperate move, leading Hannibal to comment that they might as well have handed themselves over to his men in chains. What was left of the Roman cavalry fled.

On the Carthaginian right, the light cavalry under Hanno held its own against the Roman-allied heavy cavalry. Suddenly, Hasdrubal’s heavy cavalry appeared to help them. It seems that, after defeating the Roman heavy cavalry, they actually rode around the rear of the Roman army until they reached their comrades on the opposite wing. It was a prodigy of coordination and command. The Roman-allied cavalry broke and fled. The Roman army no longer had any cavalry. For them, Cannae was now entirely an infantry battle—and it was well under way.

While the cavalry clashed, the Roman legions had advanced. The Roman infantry pushed against the Celts and Spaniards in the center of the Carthaginian line. Vastly outnumbered, the Celts and Spaniards in turn retreated backward carefully, changing their position from one of billowing outward to curving inward. As stated in chapter 1, Hannibal’s entire battle plan depended on the infantry line bending without breaking. The Celts and Spaniards had to hold on long enough for his cavalry to neutralize Rome’s horsemen, at which point the Libyan troops on the wings would spring into action. The Celts and Spaniards had to maintain an orderly, fighting retreat while observing fellow-soldiers dying all around them. Hannibal’s casualty figures show just how heavy a burden the center of his line bore: 4,000 of his 5,500 fallen infantrymen were Celts.

The Celts’ famous love of battle might have kept them on the field, but only professional training and seasoned officers could have maintained their order—that, and the presence of Hannibal himself among them, on horseback, and protected by a ring of bodyguards, but close enough to the front that he ran a risk.

Nine out of ten armies would never have been able to execute the maneuver. Most forces would have folded under a blow as hard as the one the Romans struck. Yet Hannibal’s army not only bent without breaking, it then executed a series of countermaneuvers that were as breathtaking as they were devastating.

The Romans advanced so far against the enemy center that they marched alongside the two contingents of Libyans on their flanks. When that happened, and when the signal came that the Carthaginians had demolished the Roman cavalry, the Libyans got their order to spring into battle. They turned inward and marched against the enemy. With the Libyan front pressed against the Roman flank (and with no cavalry to protect that flank), the Romans were at their most vulnerable. On top of that, the Romans were tired; the Libyans were fresh.

Bloody Symphony

Still, what happened next was not preordained. If the Roman flanks had consisted of veteran troops and if they had been well commanded, then at least some units might have been able to turn and punch their way through the Libyans. But the flanks were Rome’s newest and least experienced legions. They probably panicked and fled toward the center, tripping up the more experienced troops there in turn. That best explains why the Roman push against the Carthaginian center ran out of steam, even though the Roman consul Paullus rode there from his place on the right wing, in a vain attempt to rally his men.

For the Libyans what followed was, as Livy says, “slaughter rather than battle.” For the Romans trapped in Hannibal’s vise, it was a foretaste of hell. Every sense was tormented. Sounds included horns and trumpets, war cries in a half dozen languages, the thud of tens of thousands of marching feet, the thunder of hoof beats, the clash of iron, and the screams of the dying. Smells ranged from the slaughterhouse stink of bloody entrails or the more ordinary stench of sweat, vomit, urine, and feces. The scorching heat of a midsummer day in southern Italy, under the weight of arms and armor, touched everyone and left a dry taste in the mouth. The dust churned up by the local south wind blinded some; others had a clear sight of the field so covered with blood and slippery corpses that just standing was difficult.

And then there was Hasdrubal’s cavalry. After coming to the aid of Hanno’s men against the allied cavalry, they left the light cavalry to polish off what was left of the enemy horsemen. Now, in a move of extraordinary generalship, Hasdrubal had his men ride against the rear of the Roman infantry. Hasdrubal’s horsemen charged the Romans again and again from several different directions. It was another blow to the enemy’s morale. Had the Romans been more experienced and better led, they might have fought their way out of here too. But they did not.

With this move, the Carthaginians closed the ring. Between Celt and Spaniard infantrymen in front, Libyans on the wings, and Hasdrubal’s cavalrymen in the rear, the Romans were surrounded. It was a complete envelopment, which makes Cannae a classic of the military art. Many have admired it, most famously the German general Alfred Graf von Schlieffen, who designed a new Cannae on a vast scale to surround the entire French army across hundreds of miles in 1914—but when his plan was tried, it failed.

There were so many Roman dead: about 48,000, if not more, or more than half of the Roman army. Some of them were still alive the next morning, when Carthaginian soldiers roamed the battlefield and slaughtered the wounded. Few battles in human history have produced anything like that amount of carnage.

The roll call of the dead was a who’s who of the Roman elite. It included eighty senators or men eligible for membership in the Senate; twenty-nine colonels (to give the equivalent rank of the military tribunes); numerous ex-consuls, including one of the consuls of the previous year; and the consul Paullus, one of the two commanding officers of the Roman army. No names of Carthaginian casualties are recorded, but they may have included senior commanders—for, if they were any good, senior officers would have risked their lives to lead their men, as many still do today.

Cannae was a triumph for Hannibal. It demonstrates the many facets of his supremacy in battle: his agility and good judgment, his tactical sophistication and refinement, his timing and rhythm, his mastery of deception, his superiority in infrastructure, his knack of choosing the right officers and of holding them on the proper leash—loose enough to leave them the initiative but tight enough so they followed his plan—and his skill as a morale builder for his entire army. Divine Providence played a role as well. Hannibal conducted the battle like a symphony; as it turned out, not a note was out of tune.

Cannae was Hannibal’s greatest victory. It was also the bloodiest defeat in Roman history. Inexperienced citizen-soldiers had turned out to be no match for hardened professionals led by a brilliant general. Amateur Roman armies had led a tiny city-state to the mastery of Italy and the central Mediterranean. Now, though, the Roman way of war was dead. As the sun went down on August 2, 216 B.C., many might have wondered: Was Rome itself finished?

Not Publius Cornelius Scipio. This young military tribune (colonel) was one of the few Roman soldiers—about 15,000 out of 86,000 men—to survive. Another 19,000 men were captured, which leaves about 4,000 soldiers whose fate is unknown. Like many of the Roman escapees from Cannae, Scipio sought refuge at Canusium—it was nearby, on a defensible hill, and loyal to Rome. There, he rallied the wavering and faint of heart, promising them that Rome would rise again.

Fate would give Scipio the chance to make good on that promise.

PHARSALUS

Ancient Thessaly was known for witches and war. The witches were supposed to have harnessed the power of the moon. The warriors took advantage of the earth. A region in central Greece, Thessaly, features a plain that was made for the clash of armies: wide and flat, with rivers running through it for anchoring one’s flank. A ring of mountains closes the region in, as if to accentuate the drama. It was here that Caesar and Pompey settled their feud.

Days of Decision

The thirty days from early July to early August 48 B.C. (early May to early June by the solar calendar) decided the contest between Pompey and Caesar. Pompey counted on hunger and misery to soften up the enemy to the point where his army could deliver the final blow—if his opponents didn’t collapse on their own. What he didn’t count on was Caesar’s ability to do the impossible.

Having rallied his beaten troops at Dyrrachium, Caesar next marched them rapidly over miserable terrain, including two hundred miles through the Pindus Mountains, and into Thessaly. He then proceeded to secure food for his hungry men in a rough, brutal, and effective manner. The word had got out about Caesar’s defeat at Dyrrachium and most cities, even those allied to Caesar, now feared Pompey too much to open their gates. So Caesar opened them himself.

He chose the small city of Gomphi, strategically located on the main pass into Thessaly from the west. Gomphi was rich and full of supplies. The authorities begged Pompey for help, but he had not reached Thessaly yet, which gave Caesar a free hand. It took only an afternoon for his army to storm the walls. For once, they had their commander’s permission to plunder, and they did. The soldiers ate and drank themselves silly and took out their frustrations on the population. Twenty of the town’s leading men were found dead in an apothecary shop; they preferred to take poison rather than face Caesar’s men. As soon as the news spread, the people of all the cities of Thessaly opened their gates, except Larissa, which had a substantial Pompeian garrison to protect it. At a stroke, Caesar’s policy of terror boosted his army’s morale and provided allies and supplies.

Caesar’s drunken and bloated men would have made a prime target for Pompey but he was about a week behind them. Unlike Caesar and his forced march through hell, Pompey made a stately progress to Thessaly, eastward along the via Egnatia and then south by a relatively easy route to the city of Larissa. Pompey took his time, but demonstrating self-confidence might have seemed more important to him than rushing to deny a few days of rest to a badly bloodied enemy.

We would like to know what Pompey was thinking during this crucial period, but the general never told his own story. Caesar and his allies dominate the written record. As often in ancient history, we have to read between the lines and apply common sense to reach a satisfactory account. Here is my reconstruction of the battle.

As Caesar pulled out of Dyrrachium, Pompey consulted his colleagues. Afranius, one of the generals who had lost Spain, proposed going westward: to use their command of the sea to reconquer Italy, to employ that as a base to take Gaul and retake Spain, and then finally to go after Caesar. Pompey turned down this advice. He rightly recognized that his strategic goal was not territory but Caesar’s army. Politically, Pompey’s base was in the east, and if he shifted his forces westward, some of his eastern supporters might withdraw their men and cut off their supply of money.

Pompey also considered the reinforcements that had arrived in Greece. While at Dyrrachium, he had asked the governor of Syria, Metellus Scipio, to bring two veteran legions to Greece, and they were already there. They had tangled with the forces that Caesar sent eastward from Dyrrachium to meet them: two legions under Lucius Domitius Calvinus, which defeated Scipio in one skirmish, and one legion under Lucius Cassius Longinus, which Scipio defeated in another. Of course, Pompey could have evacuated Scipio’s legions by sea, but that would have cost Pompey prestige and, again, conceded the east to Caesar.

Besides, Pompey believed it was possible to defeat Caesar’s army in Greece. He still hoped to avoid a pitched battle because Caesar’s soldiers were “disciplined and desperate men.” So Pompey made “the most prudent calculation to protract the war and wear out the enemy by hunger from day to day.” But unlike before, he was now willing to think the unthinkable.

The sources tend to blame Pompey’s advisers and his own weakness for listening to them. Hotheaded and ignorant of war, they thought Caesar was finished, if only Pompey would give the final push. Some had lost their fortunes and were eager to get their hands on the property of Caesar’s supporters. Many distrusted Pompey and his ego: he was “more reserved, not better” than other tyrants and would-be tyrants, as Tacitus put it. Caesar’s lieutenants fought for Caesar; Pompey’s fought for senatorial government. There was talk of getting rid of Pompey once they had finished off Caesar.

Also, they accused Pompey of dragging the war on longer than necessary. Domitius Ahenobarbus, the man who lost Corfinium a year before, sneered that Pompey was a second Agamemnon, referring to the pompous supreme commander in Homer whose power lasted only as long as the war against Troy. Another senator, Marcus Favonius, complained that, thanks to Pompey’s sluggishness, they would never get back to Italy in time for this year’s figs. Some of Pompey’s eastern allies joined the chorus and demanded a pitched battle.

At last, Pompey gave in, like a ship’s captain surrendering the rudder in a strong storm—as Lucan later put it. Pompey agreed to fight a pitched battle. The question is, was it out of weakness of character or was it a considered decision? If the latter, was his reasoning military or political? The sources offer various motives. One writer says that Pompey saw the danger of battle, but his men forced him into it. A second disagrees, and concludes the problem was Pompey’s need to please as well as his thirst for glory. Another author says simply that some god misled Pompey.

It is hard to believe that the man who stood up to Caesar at Dyrrachium caved in to Favonius and his figs now that the army was in Thessaly. More likely, Pompey changed his mind, half out of hope and half out of fear. In his assessment, Cicero says that Pompey had finally begun to have confidence in his troops after their recent success; he forgot that they were merely an inexperienced and hastily collected assortment of men. But Cicero wrote in hindsight, two years later.

At the time, Pompey might have felt that it was now or never. By giving Caesar breathing space in Thessaly, Pompey had made a mistake. Caesar’s army was, obviously, not starving, but they had to keep moving to find new supplies. With the harvest about to come in, they would soon be able to feed themselves for months, and then, they could unleash ruin. Pompey knew that as long as Caesar was alive, he was dangerous and unpredictable.

Meanwhile, his own army was not likely to improve. It had just gained two veteran legions under Metellus Scipio. That and the wind at its back after Dyrrachium had made it strong—for now. With the commanders pulling in opposite directions, Pompey probably wondered how long its present strength would last. He could comfort himself with what the defector Titus Labienus, Caesar’s former lieutenant, maintained: that Caesar’s army was no longer the fierce force that had conquered Gaul. Military and political logic alike now said to Pompey that fighting a pitched battle was the best of several bad alternatives. Pompey’s judgment was intelligent, reasonable, and wrong.

Indeed, it’s difficult to convince a proud, well-fed, and well-supplied army not to fight. Memnon tried and failed to make the case before the Granicus; Fabius met the same fate before Cannae; now it was Pompey’s turn.

And so, in the end, Pompey allowed himself the luxury of hope. The classical writers on war would have bristled. “Hope is a pacifier to danger,” wrote Thucydides. War, as he knew, rewards realism and punishes dreams. The dark 3:00 A.M. of the soul looked Pompey and Caesar in the face. Caesar stared back; Pompey flinched.

The Crisis of the Chiefs

Pharsalus lies in the heart of Thessaly, at the southern edge of the central Thessalian plain, astride both east-west and north-south roads. The mountains sit just south of the town, while the river Enipeus flows north of it, and the foothills of other mountains rise north of that: the valley is about five miles wide at Pharsalus, while it narrows to the east and opens up to the west. It was in the vicinity of Pharsalus that Pompey and Caesar met in pitched battle. The battle probably took place north of the river: between the Enipeus and the hills lying between the modern village of Krini and Mount Dogandzis. The date was August 9, 48 B.C., by the Roman calendar; June 6, 48 B.C., by today’s solar calendar. It was a hot, steamy, summer day.

To understand the battle, first turn the calendar back a few pages to each army’s separate arrival in the area. Caesar got there first. About seven days after Gomphi, Caesar made his camp outside Pharsalus in the fertile plain. It was flat and open farm country, where his men could easily harvest the grain that was about to ripen. Perhaps he placed his headquarters on a low hillock with a good view of the countryside. He was near the road that went north to Larissa, Pompey’s headquarters in Thessaly, and just north of the crossing of the Enipeus River. This strategic spot gave Caesar control of the terrain: not only Pharsalus and the southern half of the plain but also the way south to Boeotia and its rich farm country. It was an apt place to wait for Pompey. He arrived a few days later and camped in the foothills several miles to the north.

For several days, Caesar tried to tempt Pompey down from the hills to fight on the plain. Caesar lined up his men for battle on the low ground, while Pompey lined up his men in the foothills. Pompey refused to descend, perhaps because he was hoping that Caesar’s men were hungry and desperate enough to attack an enemy on the high ground. When they declined, Pompey finally sent his men down to the plain to fight on August 9.

It was early morning. Caesar had given up on fighting a battle here. He decided to move his camp to a hill town ten miles to the northeast, where he expected to find more food. The men were already taking down their tents when suddenly, scouts reported the enemy’s deployment. Caesar made a quick decision and addressed his men: they would have to change plans and prepare for battle. One source reports that Caesar told his soldiers that they would finally be able to fight other men instead of having to fight want and hunger. Caesar himself states his words as “Let us be ready in our hearts for a fight. We won’t easily find a chance like this again.” He ordered a purple tunic to be hung from the commander’s tent, the Roman sign for battle, and at the sight his men supposedly shouted for joy. They were no ordinary army—they were Caesar’s men. Rarely in history has one man’s leadership tied his soldiers more closely to him.

It was the moment Caesar had been waiting for. It was the supreme battle. It was, as the poet Lucan puts it, discrimina ducum: “the crisis of the chiefs.”

The two armies lined up on roughly a north-south axis, bounded by the foothills to the north and by marshy ground around the Enipeus to the south. The battle lines stretched for about two and a half miles. The Caesarians were in the east, the Pompeians in the west. Caesar deployed about twenty-two thousand heavy infantrymen from eight legions and one thousand cavalrymen. There were also light-armed troops from northern Greece.

Caesar arranged his men in the standard Roman formation: three lines, with the best units on the flanks. The battered Legions VIII and IX were combined into a single unit on the left flank, commanded by Mark Antony. Caesar’s best legion, the Tenth, held the right flank, under the command of Publius Sulla. Domitius Calvinus commanded the center. Caesar massed his cavalry on the right flank. He left another two thousand heavy infantrymen to guard his camp.

Pompey deployed a much bigger army, of about seven thousand cavalry and perhaps as many as forty-five thousand heavy infantrymen: nine Roman legions and the best of his Greek allied contingents. Pompey too deployed his infantrymen in three lines. He placed his best legions strategically: on the left flank, the two legions that had previously served with Caesar, commanded by Domitius Ahenobarbus; in the middle, the two Syrian legions under Scipio and, on the right flank, a legion from Cilicia (southern Turkey) along with cohorts brought over from Spain, all commanded by Afranius. In between the best units Pompey deployed the rest of his heavy infantrymen, including two thousand “beneficiaries,” junior officers whom he had personally promoted. He placed perhaps four thousand heavy infantrymen on garrison duty in his camp and the forts nearby.

The two commanders, each on horseback, spent most of the battle opposite each other: Pompey on his left flank, Caesar on his right.

Most of the legionaries in the two armies were Roman citizens, Italians by origin if not current residence, since many had settled in the east. The two cavalries were each a mixed lot. Caesar’s horsemen were in large part Gauls and Germans. Pompey’s cavalry included a large contingent of Roman aristocrats, the sons of senators and knights. But it also contained thousands of men from the east, representing a diverse group of peoples from Greece to Egypt, a few of them even kings and princes. It was a coat of many colors.

Ever the tactician, Pompey planned no ordinary battle. He knew that his infantry couldn’t beat Caesar’s veterans, but he reckoned that it wouldn’t have to. Having missed an opportunity to use the cavalry at Dyrrachium, Pompey decided to stake everything on them now. He would leverage his cavalry’s superiority in numbers, equipment, and supply. Add to that his light-armed infantry troops: slingers and archers, most of them Greeks, Syrians, or other easterners.

Pompey’s plan was to mass most of his cavalry on his left flank: about six thousand men, commanded by Titus Labienus. The rest of Pompey’s cavalry, a small force of six hundred, guarded his right flank. At the start of the battle, Labienus and his six thousand cavalry would charge Caesar’s right flank and then circle around to his rear. At the same time, several thousand slingers and archers—the artillery of the time—would strike from a distance and soften up the enemy lines. Labienus’s horsemen would drive off Caesar’s insignificant cavalry, charge into the flank of the enemy infantry, and cause a panic. It would take a series of attacks, withdrawals, and renewed attacks, but eventually the cavalry would fold up the enemy’s right wing and drive it toward his center.

Pompey gave his legions a simpler task: hold the enemy. Normally, Roman infantrymen began a battle by throwing their javelins and advancing, and then closing in with their swords. But at Pharsalus, Pompey issued an unusual order: he told the legions to stand still. A regular advance might cause Pompey’s inexperienced lines to fall into disorder. He hoped that, by standing in place, they might break the impetus of Caesar’s attack while maintaining their own good order. They would force Caesar’s men to march further to reach them, which might tire the enemy. Meanwhile, his men’s immobility might make it easier for them to wield their shields against enemy javelins. They might even be able to counterattack, but the main thing was to provide a strong wall while Pompey’s cavalry and light-armed troops hammered Caesar’s men.

It would have been a good plan if carried out by Alexander’s or Hannibal’s seasoned horsemen. Or, rather, it would have been a good plan but it lacked the element of deception. One wonders what Labienus thought of it, because back in Gaul, he had been a master at tricking the enemy. No tricks now. Caesar, who could see what Pompey was up to with his cavalry, knew how to respond. He withdrew individual cohorts from the third line of each of his legions and formed an unusual fourth line, which he positioned behind the cavalry, probably at an oblique angle. This weakened the third line but, as usual, Caesar was willing to take a risk. The enemy could not see this fourth line, which meant that Caesar could add surprise to the advantages of his terrible new weapon. The matchless professionalism of his troops allowed Caesar to take chances, but this was a move of supreme audacity, something that only an exceptional commander would have dared.

About eighty thousand men had now lined up against each other, with more guarding the camps nearby. Pompey and Caesar, each on horseback, rode down the lines with their final words to incite fellow Romans to kill each other. The men’s shouts and cries rang out in answer across the valley.

Once the trumpets sounded the start of battle, little worked out as Pompey had planned. Caesar’s legionaries ran forward against the Pompeians to throw their javelins, but when they noticed that the enemy standing still, they stopped. A dazzling display of discipline, the halt let them catch their breath and then start up again, full of energy for the attack. Even so, Pompey’s men managed to hold their ground. Locked in combat, each side soon drew its second line into the fight. The roar of battle, as the poet Lucan imagined it, included the weight of groans as if from one immense voice, the clanging of armor against crashing bodies, and the sound of sword breaking against sword.

The decisive action took place on Caesar’s right flank. Pompey’s cavalry, six thousand strong, “its wings deployed across the entire plain,” as the poet says, thundered toward the enemy. Archers and slingers followed on foot behind them, firing so many missiles so rapidly that you could almost imagine them melting in the heat. Just as planned, the assault forced Caesar’s cavalry from the field. Led by Labienus, Pompey’s cavalry redeployed in squadrons and began to surround the infantry lines on Caesar’s exposed flank. It was the high-water mark of Pompey’s effort. Then Caesar ordered his fourth line to advance. Suddenly, the Pompeian cavalry faced not an infantry’s flank but its front, with a wall of iron-tipped spears in its path. It was an obstacle that ancient cavalries never succeeded in overcoming.

“No circumstance contributed more than this to Caesar’s victory on that day,” writes Frontinus, “for as soon as Pompey’s cavalry poured forth, these cohorts routed it by an unexpected onset, and delivered it up to the rest of the troops for slaughter.”

The key to victory, according to some sources, is what Caesar told his infantrymen: aim for the enemy’s face, on the principle that vanity would make an elite horseman turn and flee. But that was nothing new; Alexander’s men too aimed for the enemy’s face. More likely, the real cause of Pompey’s defeat was panic. When the cavalry piled up against the unexpected obstacle of Caesar’s fourth line, it probably lost its nerve. Experienced men might have coolly retreated, re-formed, and attacked again, once the enemy gave them an opening. Not Pompey’s rookies. Discipline and formation were gone; all that was left was a mad dash back to safety. If Labienus tried to get the cavalry back into formation, to strike Caesar’s fourth line in its rear in turn, it was a vain attempt.

And that was that. Caesar’s fourth line massacred the archers and slingers who had been left in the lurch. Then, the model of discipline, they turned and crashed into the left flank of Pompey’s infantry line, attacking it in the rear. Caesar meanwhile ordered his third line of legionaries out of reserve and into action. Pompey’s infantry was now under attack from two sides, and, on one of them, pounded by fresh troops. It was too much: after a slow retreat at first, the Pompeians ran.

As he surveyed the ruin of his enemy, Caesar is said to have remarked, “They wanted this. In spite of all my achievements, I, Gaius Caesar, would have been condemned if I hadn’t asked my army for help.”

Pompey had already left the field and returned to camp. The battle of Pharsalus, as he well knew, was over. The war, however, would go on. It was his job now to try to salvage as much of his army as he could.

Brilliant strategist, masterful tactician, tireless organizer, cunning diplomat, Pompey lacked only one thing: he wasn’t Caesar. Pompey understood neither Caesar’s audacity nor his agility. Knowing that Caesar’s army was strained to the breaking point, he could not conceive of the magic of Caesar’s leadership. The worse things got, the stronger Caesar made his men. Pompey couldn’t imagine Caesar coming back from the defeat of Dyrrachium and beating him in pitched battle. It took nearly superhuman effort, and that is precisely what Caesar brought to bear.

Flight

The sources paint a picture of Pompey in despair, but it is hard to trust them. In all likelihood, he tried to organize the defense of his camp. Legionaries, Thracians, and other non-Roman soldiers manned the ramparts, but few of the soldiers who streamed back from the battlefield joined them: most of them kept running. The midday sun was blazing and even the victors were exhausted, but Caesar urged them to attack. The Caesarians stormed the camp. Pompey’s officers led as many defenders as they could into the hills.

As soon as the fate of his camp was sealed, Pompey rode off through the back gate with a bodyguard of thirty cavalrymen. They headed toward Larissa.

Meanwhile, Caesar’s men were itching to gorge themselves on the luxurious food and to loot the silver plate laid out under ivy-covered bowers in Pompey’s camp. Caesar, however, drove them forward in pursuit—another sign of their discipline. They found the Pompeians on a nearby hill that lacked water, and immediately began to surround it with an earthwork. But the enemy fled and took to the ridges in the direction of Larissa. Caesar would not let them escape. He divided his forces and left most of them to defend his camp and Pompey’s. Taking four legions, he tracked down the enemy to another hill a few miles away, and had his weary men immediately begin building a wall to cut them off. As night began falling, the Pompeians finally sent representatives to negotiate surrender. Caesar offered lenient terms and the enemy surrendered the next morning. Only a few senators had escaped during the night.

The results of Pharsalus were, as often in great battles, lopsided. Caesar lost only 230 men (including 30 officers), according to his claims, but other writers raised the figure to 1,200 men. Caesar says his men killed 15,000 Pompeians and accepted surrender from another 24,000; another eyewitness source estimated Pompey’s losses at only 6,000 men. One thing is certain: the dead included Domitius Ahenobarbus, Caesar’s archenemy, who was killed by Caesar’s cavalry as he fled from Pompey’s camp to the nearby hill. Caesar claimed the honors of victory: 180 military standards and 9 legionary eagles.

The same day that the last Pompeians surrendered, Caesar hurried to Larissa, but Pompey had already escaped. He was fleeing to the coast, ready to board a ship to go east. Pompey had no intention of giving up. Why should he have? He still claimed the title of supreme commander of the Roman state, and he was not without the means of backing it up. He still had about seven thousand soldiers at Dyrrachium. He still commanded a fleet of six hundred warships. He still knew more powerful people who owed him favors than most Romans could ever dream of meeting.

So Pompey slipped out of Caesar’s hands and prepared to continue the struggle. Caesar followed, eager to end the war.

THE ESSENCE OF DECISION

Gaugamela, Cannae, and Pharsalus: these killing fields saw too much skill not to impress and too much blood not to appall. Six thousand to seven thousand men were killed at Pharsalus, on a conservative estimate. Gaugamela could hardly have been less bloody, but Cannae wins the prize. With roughly 55,000 men killed—most of them Romans—it was one of the bloodiest days in human history. It gives one pause to think that most of the damage was inflicted by professional killers.

The three winning armies moved with grace and precision. Alexander’s men adopted a new battle formation as easily as a new pair of shoes. Hannibal’s Africans turned on the legionaries with parade ground exactness. Caesar’s legionaries stopped in midcharge as if doing a favorite dance step. Alexander’s and Hannibal’s army each blended cavalry and infantry as smoothly as liquid oxygen and hydrogen in rocket fuel—and as explosively. What Caesar’s force, with its inadequate cavalry, lacked in versatility, it made up for in suppleness.

The genius of the winning generals is equally impressive. Each man correctly analyzed his opponent’s strengths and weaknesses and responded with ingenuity and pluck. By forcing the enemy into a slugging match on the Macedonian right wing Alexander bogged down the Persians’ best cavalry and opened a path toward Darius. By neutralizing Rome’s cavalry, Hannibal cleared the field for a choreographed massacre of the Roman legions. By surprising Pompey’s cavalry with a solid front of fresh infantrymen, Caesar destroyed his opponent’s offensive capability.

Each of the winning commanders displayed a healthy mix of respect and contempt for his foe. Through spying or intuition, each of them guessed his enemy’s plan. Caesar knew that Pompey’s cavalry had the numbers to destroy him but he was confident that it lacked the backbone. Hannibal sized up the legionaries’ power and their clumsiness. Alexander knew what a Persian cavalry charge could do, but he had faith that his light-armed troops, specialists in darting between horsemen, could stop the enemy in his track.

Each of the winners took operational and tactical risks. Alexander and Hannibal had bodyguards but fought in the front; Caesar held farther back but was on the battlefield. Caesar took the chance of thinning out his third infantry line in order to form a fourth line to throw at Pompey’s cavalry. Hannibal knew that his Celts were hard to discipline, but he counted on his ability to keep their battle line bending in retreat without breaking. Alexander bet that his left flank under Parmenio could hold out long enough against the enemy’s charge for him to destroy Darius.

We must also salute the winners’ ability to hold their armies together. Although Alexander’s army had a relatively easy time of things on the road to Gaugamela, they still faced fear, as shown by their responses first to an eclipse and then the sight of Darius’s huge force. Alexander had to reassure them.

Hannibal’s force had just faced six difficult months against Fabius. But those deprivations were nothing compared with what they had suffered crossing the Apennines, and that, in turn, paled next to the problems of crossing the Alps. So, by the time they faced an enormous enemy army at Cannae, Hannibal’s men were ready.

Caesar’s army probably wins the prize for deprivation. Between January 49 and August 48 they covered more territory than even Hannibal’s men. They had no victories in pitched battle to buoy them, and they suffered heavy casualties in the siege of Dyrrachium. They were rarely permitted to loot and were often late in being paid. Within a month of enduring death, hunger, and exhaustion, they turned everything around and won a smashing victory.

Each of the three winning armies was part band of brothers, part gangland family. They fought for honor and loot. Principles were optional. Alexander claimed to be waging a war of revenge and a preventive war, but neither claim was convincing; he wanted to conquer an empire. Caesar declared that he was fighting for freedom and status, but the future dictator’s defense of popular power rings hollow, and his preoccupation with rank attracts few supporters today. Hannibal’s claim of self-defense against Roman aggression is more persuasive but it is hard to separate it from his lust for conquest.

It is easier today to sympathize with the defenders. The Persians and the Romans were each defending an empire, but it included their homeland. Pompey was as selfish as Caesar but his supporters truly believed in liberty, at least as narrowly defined: the freedom of the few to guide Rome toward the public good, as they saw it.

Each battle saw such a one-sided outcome that it begs the question of what the loser was thinking by ever agreeing to a pitched battle in the first place. In hindsight, Darius, Paullus and Varro, and Pompey each accepted a fight that he should have avoided. A Fabian strategy of refusing battle might have worked as well for them as it had for its namesake. The strategy might have played out quite differently in each battle.

Instead of leading Alexander to Darius, the Persians might have contested his crossing of the Euphrates and the Tigris. They could have burned crops and emptied granaries. With their horsemen and archers tailor-made for raids, they could have harassed Macedonian foraging parties. Meanwhile, they could have forced Alexander to fight for every city he wanted instead of allowing him to negotiate surrenders. In short, if the Persians had used the Fabian strategy, they would have made Mesopotamia a desert. If Alexander still managed to cross it, they could have blocked the Zagros Mountain passes into Iran. They could have removed the treasures of Susa and Persepolis and brought them eastward for safekeeping.

If the Persians had made conditions harsh enough, the Macedonians might have had enough. They might have forced Alexander to accept Darius’s offer of the western provinces and turn back.

The Romans who faced Hannibal had to do only what they did before Cannae: not fight in Italy. They should have remained on the defensive while harassing Hannibal and denying him supplies. At the same time, they should have pressed their Spanish offensive. Eventually, they would have forced him to leave Italy and defend Spain. That would not have ended the war, but by sparing Rome the defeat of Cannae, it would have kept Rome’s allies from defecting and increased Rome’s resources for the struggle ahead.

In Pompey’s case, things might have gone differently if he had refused battle. At the time of Pharsalus, he had launched a naval offensive in the west. One fleet had attacked Sicily, another was blockading Caesar’s remaining troops in Brundisium. If successful, as they probably would have been, they would have cut off Italy from its food supply and kicked the props out from under Caesar’s supporters in Italy. Spain was already showing signs of unrest against Caesar’s governor, and these would have grown with Pompey’s success.

Meanwhile, Pompey might have frustrated Caesar in Greece. Imagine a continual series of raids by Pompey’s cavalry on Caesar’s troops trying to cut down ripe grain in the fields. Caesar would no doubt have struck back, but with hungry and tired men. Imagine the news from the west seeping into Caesar’s camp. If Pompey held his army together, he might have tempted traitors in Caesar’s ranks to join him, just as he had done at Dyrrachium. That might have given Pompey an opening, if only for an assassin, but a dagger could have ended Caesar’s quest.

If avoiding pitched battle would have worked out well, why then did the commanders agree to fight? For one thing, hindsight isn’t history, and there is no guarantee that a Fabian strategy would have worked. For another, pitched battle had its own rewards. Ancient culture put a higher premium on honor than on cunning. To turn down battle was to risk losing face, which might have led waverers to switch sides. Battle was risky but making a decision was easy and quick. A Fabian strategy meant a long war and more chances for a bronco like Caesar to buck.

The losing generals did not go into battle without preparing to meet a dangerous enemy. All of them put together big armies that greatly outnumbered their opponents’. Darius recruited excellent horsemen, made plans to compensate for his lack of heavy infantry, and chose his battlefield carefully. Paullus and Varro massed their legionaries tightly in order to compensate for the men’s inexperience and to increase the odds of breaking through the enemy line. Pompey did not seriously consider a pitched battle before first bruising Caesar’s army in siege warfare. Still, he recognized the weakness of his infantry and rested his plans on his cavalry. In short, the losing generals tried to exercise due diligence, but they failed.

The victors would never have won, of course, unless Divine Providence had convinced their enemies to fight. That same providence gave them the resources to win. They owed some of their success to a general’s willingness to engage in terror or to brand himself as a god’s son. A more important factor was the superior professionalism—the better infrastructure—of the victorious army. The ability to feed their men in hostile country was also a matter of infrastructure. Then there was the leadership by which a commander bound his officers and soldiers to him. Next came the agility to come up with new tactics and the audacity to carry them out. Finally, there was the good judgment of the commander, the combination of intuition and expertise that had him do just the right thing at just the right time. Nothing played a greater role in making Gaugamela, Cannae, and Pharsalus into virtuoso pieces.

The day after battle, the question was what each of the participants would do to justify the terrible carnage. Could the winners translate success on the battlefield into victory in the war? Could the losers rally their societies in defeat and continue the war? We turn to those questions.