The Battle of Cannae on 2 August, 216 BC serves as a classic example of a double-envelopment maneuver, a way for an inferior force to defeat a superior force on open terrain. Hannibal is still studied in military acadamies.
The battlefield is located in the Apulian plain on the right bank of the Aufidus (modern Ofanto) River, about six miles south of Canosa di Puglia, which itself is midway between Bari and Foggia on Italy's east coast.
The army of Hannibal, fronting west, stood to the left of Aufidus (Ofanto) in the vicinity of the village Cannae,(2) situated near the mouth of the river, and opposite the troops of the consuls Gaius Terentius Varroransferred and Lucius Aemilius Paulus.
The Opposing Forces
Rome put a massive infantry force into the field against Hannibal. The combined forces of the two consuls totalled had 55,000 heavily armed men, 8,000 lightly armed men, 6,000 mounted men - involved in the actual battle - and, in the two fortified camps, 2,600 heavily armed men, 7,400 lightly armed men (a total of 10,000) at his further disposition, so that the total strength of the Roman army amounted to 79,000 men. It is known from Livy that the First, Second, and Third legions took part in the battle. Paullus was with the First Legion. Publius Cornelius Scipio ('Africanus'-to-be) was also there, at the age of about nineteen years with the Second legion. (Green as he was, though, he - along with Pulcher, from the Third legion - was given temporary command of the remnants of the Roman army after the battle and before Varro was heard from.) Also present was Fabius Maximus, the son of the ex-dictator.
Hannibal's troops amounted to probably only 32,000 heavily armed men (including only 12,000 Carthaginians, the rest being Gauls and Iberians), 8,000 lightly armed men, 10,000 mounted men (a total of 50,000). Moreover, Hannibal's troops were most likely not of the same quality as Roman legionaries. They were a colourful mix of Gauls, Spaniards, Numidians and Carthaginians. A lot is made of the phychological impact his elephants had on terrified Roman troops. But by the battle of Cannae all Hannibal's elephants had died.
In theory, the Roman sledgehammer should have crushed the Carthaginian menace, but for the way it was to be wielded.
Disagreement between the Consuls
Livy and Polybius report a daily alternating commandership of the forces, although there is some doubt about how important an issue this was - this literary device may have been used to whitewash the role of Paulus in the disaster. Varro was reported as being in command during the day of battle, and Paullus is reported to be opposed to a confrontation.
Hannibal's position, with a considerably superior enemy in his front and the sea, in his rear, was by no means a favorable one. Nevertheless, Consul Aemilius Paulus, in concurrence with Proconsul Servilius, wished to avoid a battle. Both feared the superior Carthaginian cavalry to which Hannibal particularly owed his victories on the Ticinus, on the Trebia and at the Trasimene lake. Terentius Varro, neverthelesss, wished to seek a decision and avenge the defeats suffered.
Dispositions and tactics:
cavalry on the flanks
Both generals wanted to employ the tactics for which their armies were best suited; we look now at why tactics influenced how the armies took their places on the battlefield. Where Varro wanted to lead a massive attack on the enemy's center and break through their lines, Hannibal planned to encircle the enemy with his cavalry. The legions were led by a man named Servilius, who was a war tribune--a position of command that rotated among six officers each year.
The dispositions dictated the course of the battle. Both sides put their cavalry on the flanks. Varro drew up in three lines, which was the traditional battle formation. Hannibal made two adjustments in his setup. First, the weaker Gauls and Spaniards were pushed out in an arc, while the stronger Africans were held back on at each end of the infantry line. While Hannibal was outnumbered in infantry 2:1, his cavalry was superior to the Romans, expecially on his left.
Hannibal first masked his moves as he drew up his army, by placing his light slingers and spearmen at the front. Behind them, he positioned his Celtic and Spanish swordsmen in a crescent in the center. On his left wing he stationed his Celtic and Spanish heavy cavalry, on the right he stationed his light Numidian cavalry.Hannibal put his most reliable (African) troops on the flanks and turned his center over to his less reliable Spanish and Gallic allies. Hannibal opposed to the enemy's front only his 20,000 Iberians and Gauls, which were probably 12 files deep. The greater part of his cavalry under Hasdrubal was placed on the left wing and the light Numidian on the right. In rear of this cavalry the 12,000 heavily armed Carthaginian infantry were formed equally divided between the two wings. He placed the center somewhat forward of the flanks, making a convex crescent shape.
The lightly armed troops, destined to begin the combat, to envelop the enemy and to support the cavalry, were not much considered by either side.
Hannibal's infantry was massed in one line, while the Romans stacked their men in the usual three waves. Each side positioned its cavalry on either flank. The River Aufidus formed a barrier.
Reflecting their plan for a central assault, the Romans organized 74,000 light and heavy infantrymen into three lines.They faced a semicircle of 40,000 heavily armed infantry under the personal command of Hannibal. The Carthaginian troops included units of Libyan, Gaul and Iberian mercenaries, foreign soldiers hired to fight.
Despite the devastating defeats earlier in the war, Roman morale remained excellent. Indeed, the battle looked like an easy victory, for Hannibal was outnumbered by two-to-one.
Before the battle
When before the battle of Cannae, Varro had hung out his purple cloak as a signal for battle, "this boldness of the consul and the size of his army - double theirs - must have startled the Carthaginians. But Hannibal commanded them to their arms, and with a small train rode out to take a full prospect of the enemy as they were now forming in their ranks, from a rising ground not far distant. One of his followers, called Gisgo, a Carthaginian of equal rank with himself, told him that the numbers of the enemy were astonishing; to which Hannibal replied with a serious countenance, "There is one thing, Gisgo, yet more astonishing, which you take no notice of." And when Gisgo inquired what, answered, that "in all those great numbers before us, there is not one man called Gisgo." This unexpected jest of their general made all the company laugh, and as they came down from the hill, they told it to those whom they met, which caused a general laughter amongst them all"
According to Livy, Paullus was severely wounded in the head by a slinger right at the start of the battle (in contradiction with Polybius, who claims that Paullus was wounded only later). Eventually, he became unable to control his horse, and then his entire bodyguard dismounted to share the destiny with their commander. But the wound didn't obstruct Paullus from taking control of the army after Varro so shamelessly fled before the field was completely lost, as he essayed (in vain) to save the day. Hannibal later honored him by having his body buried with ceremonial rituals.
The Armies engage
According to Livy, about 500 Numidians pretended to desert right before the battle started. In addition to their regular weapons, they concealed swords under their tunics. They flung down their shields and javelins on the ground, and were conducted to the rear where they were told to remain. But during the battle, they suddenly picked up their weapons and proceeded to strike at the Roman rear, "causing terrible destruction, and even more panic and disorder".
Preparing for battle, Hannibal now ordered his light troops at the front to fall back and act as reserves. The Romans meanwhile acted as usual. The velites were positioned at the front to cover their position. Behind them, in the centre the main body of the legion took its position, with allied Italian infantry on either side of it. On the Roman right wing stood the Roman cavalry, on the left wing was the allied cavalry.
Both armies advanced against each other.
The Romans drove in hard, using their superior infantry to best advantage. They had their velites fall back and ploughed into their foe with their heavy infantry. The Iberian and Gallic auxiliary forces were thrown back at the impact not so much on account of the strength of the attack of the 36 Roman files as on account of the inferior armament and the lesser training in close combat. While the Gauls and Iberian infantry of Hannibal's centre line yielded (without breaking) before the drive of the numerically superior Roman infantry, until the Romans had pushed deep into the middle. The cresent of Celtic and Spanish swordsmen buckled and retreated. To the Romans this appeared to be due to their powerful drive into the opponents lines. In fact the troops had been told to retreat.
The Carthaginian light troops pulled back at the beginning had by now taken position at the rear of the crescent as well to each side of the crescent. Simultaneously with the advance of their infantry the Roman cavalry on the right wing now engaged the Spanish and Celtic heavy cavalry on the Carthaginian left.
The Libyan infantry and cavalry of Hannibal's flanks stood fast, overlapped the Roman line, and in a rear encircling movement turned to pursue the victorious legionaries.
Hannibal's cavalry gains the flanks
Map created by the Lessons of War team
No sooner had the Roman front lines commenced their attack on the Carthaginian center than the Carthaginian heavy cavalry commanded by Hasdrubal rushed the horsemen on the Roman right flank. Unable to hold their position, the Romans were splintered into small units that fled the battlefield and left their leader--consul A. Paullus--dead. The Roman right flank was left defenseless. Hannibal's Tactics: Give Ground The Carthaginian center was gradually withdrawing from the Roman assault. This was part of Hannibal's plan to win the battle: his infantry withdrew deliberately to create an even tighter semicircle around the attacking Roman forces.
Hasdrubal overpowered the weaker hostile cavalry on the right flank. The Roman knights were overwhelmed, thrown, into the Aufidus or scattered. The conqueror turned the hostile infantry and advanced against the Roman cavalry on the wing which, until then, had only skirmished with the Numidian light horse. Attacked on both sides, the Romans were here also completely routed. Upon the destruction of the hostile cavalry, Hasdrubal turned against the rear of the Roman phalanx.
The Roman infantry kept on driving into the Carthaginian lines. Forcing them back, they still felt confident that they were winning. But as they shunted forward and the opponent withdrew, the light infatnry on the Carthaginian side, though itself staying stationary as it wasn't withdrawing, began to emerge on the Roman flanks. Worse still, on the wings, Hannibal's Celtic and Spanish heavy cavalry was driving the Roman cavalry back. Combined with the advance of the Roman infantry this meant that there emerged a gaping breach in the Roman line. A large body of cavalry now separated from the Carthaginian left wing and charged across the field of battle to the right wing, where it fell into the rear of the cavalry of the Roman allies.
Though their commander, consul T. Varro, escaped, most of the Roman horsemen rode sluggish mounts and were unable to dodge the repeated Carthaginian attacks.
Closing the Circle
Map created by the Lessons of War team
By now, Hannibal's infantrymen had surrounded the Romans on three sides. Hasdrubal's cavalry came from the Carthaginian left flank to finish off the rest of the Roman cavalry. Then, both units of Carthaginian horsemen closed the ring around the Romans in the rear. Stripped of both its flanks, the Roman infantry formed a wedge that drove deeper and deeper into the Carthaginian semicircle. Hannibal's infantry surrounded its enemy on three sides--and the Carthaginian cavalry closed the circle in the Roman rear. It was no longer a fight: the trapped Roman soldiers were massacred. Of the 80,000 legionnaires and cavalry who had started the fight, 46,000 were killed and 22,000 captured. Just 12,000 Romans survived the fight.
The Roman infantry had continued to drive forward, and had driven itself into an alley formed by the light Carthaginian infantry stationed at the sides. Shielded by these Carthaginian troops, their comrades who had stayed at the rear could now swing around and come in behind the Roman army. The Roman doomed legions were encircled and beign attacked from all sides. In effect the Roman infantry had been defeated by the opposing infantry, although the returning Carthaginian cavalry helped further accellerate their victory.
The advance of the Romans was, however, checked, as soon as the Carthaginian flanking echelons, kept back so far, came up and attacked the enemy on the right and left, and as soon as Hasdrubal's cavalry threatened the Roman rear. The triarii turned back, the maniples of both wings moved outward. A long, entire square had been forced to halt, fronting all sides and was attacked on all sides by the infantry with short swords and by the cavalry with javelins, arrows, and slingshots, never missing In the compact mass. The Romans were constantly pushed back and crowded together. Without weapons and without aid, they expected death. Honnibal, his heart full of hatred, circled the arena of the bloody work, encouraging the zealous, lashing on the sluggish.
His soldiers desisted only hours later. It was a terrible slaughter. Fleeing Romans were hamstrung (that is, the pursuer rather than trying to kill the fleeing enemy simply slashed at the man's hamstring muscle, returning later to kill the crippled man). Weary of slaughter, they took the remaining 3000 men prisoners. On a narrow area 48,000 corpses lay in heaps. Both Aemilius Paulus and Servilius had fallen, Varro had escaped witha few cavalrymen, a few of the heavily armed and the greater part of the lightly armed men. Thousands fell into the hands of the victors in the village of Cannae and in both camps. Only 15,000 escaped death or capture; the survivors were placed in two special legions that were forced to remain under service in Sicily for the duration of the war, as a punishment for their failure. Roman knight's gold rings were collected in baskets and later poured out onto the floor of the Carthaginian senate.
One of the consuls Lucius Aemilius Paulus (and one of the preceding year's) were killed, as well as both quaestors of the consuls, 29 out of 48 military tribunes and 80 other senators. The other consul Gaius Terentius Varro (died after 200 BC) escaped with the remnant. Carthaginian losses were about 6,700 men,mostly Iberians and Gauls.
Hannibal once more released non-Roman prisoners.
It was the largest defeat in the history of Rome, and it put the Roman citizens in a state of emergency.
Hannibal's officers now wanted to take Rome, which was left all but defenseless. But Hannibal refused, to the distress of Maharbal, one of his cavalry commanders, who is quoted as saying. "Hannibal, you understand how to win a battle; but you do not understand how to use your victory".
Gnaeus Servilius Geminus and Marcus Atilius Regulus were proconsuls (consuls of the previous year). According to Livy and Polybius, they took care of the Roman center, and both perished with the army. Lucius Caecilius Metellus is known to have so much despaired in the Roman cause, in the aftermath of the battle, as to suggest that everything was lost and call the others to sail overseas and hire themselves up into the service to some foreign prince. Philus, the son of an ex-consul, broke those news to Scipio, and the pal, his young blood boiling hot, forced Metellus by his own stormy example to swear an oath of allegiance to Rome for all time. Publius Sempronius Tuditanus was that energetic tribune under whose leadership the Roman cohorts, trapped in the camps after the battle, were able to organize and cut their way through to Canusium. Lentulus is the one who, according to Livy, witnessed Paullus' death under Numidian javelins.
Reason for the Roman defeat
In effect, the Roman army had defeated itself. It had solely relied on the superiority of its legionaries, having lined them up and told them to advance. No use had been made of the superior numbers, other than to simply add more ranks onto the back of the advancing columns. As the Carthaginian units manouvered, nothing was done to counter their actions. One simply did what one had always done - advance. Such ignorance was most likely born from the fact that the battles with Hannibal were the largest contests Rome had ever fought by that time. Despite their earlier dealings with king Pyrrhus, they most likely had not gathered enough experience yet in such matters to be able to cope with such huge a challenge. And the superiority of their legions perhaps made them rely to heavily on their soldiers alone. In short, Roman tactics were non-existent at Cannae. The Roman force acted with brute force, charging at its dangerously clever opponent like a bull. Defeat in this battle was a blow from which Rome should be reeling for some time to come. More than ever Rome needed brilliant generals, capable men of intelligence and imagination. Rome needed a Scipio Africanus - and he was soon to emerge to deliver her from the Carthaginian menace.