The Battle of Cannae

By Johndisp

It was August the 2nd 216 BC, when Rome suffered it's greatest military loss ever. The battle cannot be considered only in loss of manpower. The loss at Cannae almost handed the Roman Empire to the Carthaginian General Hannibal. Although fewer men were lost at Teutoburg, and that battle had a more profound effect of Rome's military philosophy, the Battle at Cannae cost the Roman legions 66000 men. These men were beaten by the classic example of a double-envelopment maneuver.

In early autumn of 216 BC, the Carthaginian forces occupied the citadel of the town of Cannae. This citadel was a stockpile of Roman goods and war materials, and its loss was a huge blow to the Romans soldiers in the area. They sent emissaries to the Roman senate to beg for instructions on what actions to take against the Carthaginians. The senate decided to give Hannibal the battle he so desperately wanted, but ordered the soldiers watching his forces to wait for more men.

The senate then decided to form eight regular and civilian legions under the consuls Gaius Terentius Varro and Lucius Aemillius Paulus. These legions consisted of 55000 heavily armed men, 8000 lightly armed men, 6000 cavalrymen, and the army that was shadowing Hannibal, 2600 heavily armed men, and 7400 lightly armed men. These 79000 men would be sent to destroy Hannibal once and for all. Interestingly, Publius Cornelius Scipio, who would later become known as Africanus for destroying Hannibal at Zama, was in command of one of the legions.

Hannibal was only able to field 32000 heavily armed men, 8000 lightly armed men, and 10000 cavalrymen. In short, it was 79000 Romans versus 50000 Carthaginians. If not for Hannibal's superior understanding of tactics, his army would have surely ceased to exist.

As was standard policy when two consuls went together into battle, they alternated leadership of a daily basis. What may have played a part in the disaster was that Paulus was reportedly opposed to battle and Varro was "itching for a fight". It came to be that on the day of the battle, Varro was in charge.

Hannibal could have hardly been in a worse position to fight a battle. He had a superior army, both in men and skill, in front of him and the sea to his back. It was this situation that pushed Varro to act. He felt that he would never have Hannibal caught in a trap like this again.

Both armies wanted to play to their strengths. For the Romans this meant an infantry charge straight through Hannibal's center. For Hannibal it meant having his center hold until his cavalry could encircle the Roman legions. Who would achieve their desired effect was soon to be seen.

Hannibal formed his men in a concave shape bowed away from the Roman lines. He placed his Iberian and Gallic infantry in the center, flanked by Carthaginian and Spainish infantry on either side. On the left wing he placed his 2000 Gallic and Spanish heavy cavalry, and on the right was his 4000 Numidian light cavalry. Hannibal stationed his Carthaginian heavy cavalry near the rear of his lines. Hannibal also lined his infantry in one solid formation, while the Roman used their customary three-wave formation.

Just before the battle was started, 500 Numidians threw down their weapons and routed, or appeared to rout. In actuality, they retreated behind Hannibal's lines and waited for the heat of battle, at which time they rode around and hit the Roman rear.

As the armies closed with each other, the Roman velites fell back and allowed the infantry to do its damage. As the lines clashed, the Iberian and Gallic forces were driven backwards, but did not break. On the flanks however, the Spanish and Carthaginian forces broke into a full retreat. To the Romans, it appeared they were winning the day, but Hannibal had orchestrated the retreat during his strategy session. The Carthaginian light infantry now reinforced the "faltering" lines, and the Roman cavalry met the Spanish/Celtic cavalry on the Carthaginian left.

Between the center and the cavalry wings, Hannibal's Libyan infantry and cavalry held their ground and thus formed "walls" on either side of the Roman formation as it plunged deeper into Hannibal's withdrawing center.

As soon as battle had been joined by the infantry, Hannibal's Carthaginian cavalry had slammed into the Roman heavy cavalry, who was still engaged with the Gallic/Spanish cavalry, on the Roman right and routed them. In the vicious attack, Consul Paulus was killed. The destruction of these forces left the Roman right flank defenseless. Then Hasdrubal, who was leading the Carthaginian cavalry, took them around the battlefield and collided with the Roman cavalry on the left flank, who was still engaged with the Numidians. These forces were also routed. This left Hasdrubal free to hit the rear of the Roman lines along with the 500 Numidians who had faked a retreat at the start of the battle.

Slowly a box was forming around the Romans. The Iberian/Gallic center was slowing giving ground, but keeping a solid line in front of the Romans. The Spanish/Carthaginian forces had stopped their retreat and were being given the sides of the Roman phalanx as they marched steadily forward. And now the remainder of the Carthaginian light infantry charged around the entire formation and appeared at the Roman rear with the Carthaginian cavalry. The trap slammed shut.

Of the 79000 Romans who took the field that morning, 44000 were killed, 22000 were taken prisoner, and 13000 fled the field in defeat. In contrast, the Carthaginians lost only 6700 men and most of them were the Iberians and Gauls. The 13000 Romans who routed were rounded up by the Romans and sent to Sicily in disgrace. They would remain there until Scipio arrived and recruited them for his Africa campaign. Scipio, had made a good accounting of himself in this first battle, and had in fact organized the routed men into a regiment that kept them from being isolated and destroyed. Scipio would never forget this defeat and at Zama would pay back Hannibal in kind.

Hannibal's generals now pushed him to attack Rome. But in what was a saving grace for Rome, he refused. This refusal sparked one of those historically famous quotes. Hannibal's cavalry general Maharbal then stated, "Hannibal, you know how to win a battle, but not how to use the victory."

Never again would the Romans lose this many men in a single battle. The loss through the Roman citizens into a panic, and if Hannibal had decided to attack Rome, he likely would have either defeated them or at least forced them to sue for peace.