The Battle of Cannae

In the temple of Baal that day, there were a father and a son. The nine-year-old boy swore before his father that he would surely destroy Rome. Later, when this boy crossed the rugged Alps and invaded Rome, the Romans were shocked. No Roman general could oppose him. The name of that boy became etched in the memories of the Romans as a symbol of terror. His name was Hannibal, the protagonist of the Second Punic War, which the Romans would later call the greatest national crisis in their history.

 

The Battle of Cannae

 

1. Background

About 2,200 years ago, Hannibal from Carthage (modern-day Tunisia) crossed the rugged Alps and invaded Rome. On the plains of Cannae in southern Italy, he faced around 90,000 Roman soldiers. At this time, Hannibal commanded a force of around 50,000 soldiers, including 26,000 elite troops from Spain and 24,000 Gallic mercenaries from Gaul (modern-day France). Meanwhile, Rome had already emerged as a new power in the Mediterranean after defeating Carthage in the First Punic War. It was against this powerful Rome that Hannibal launched his challenge.

 

2. The Scale and Formation of the Armies

The Roman army, led by the consuls Aemilius and Varro, consisted of 80,000 infantry and 7,200 cavalry. Hannibal’s army, on the other hand, had 40,000 infantry and 10,000 cavalry. Though outnumbered, Hannibal had superiority in cavalry quantity and quality, and his effective use of cavalry would decide the outcome of the battle. The Romans left 10,000 troops behind in camp, while the remaining 80,000 were deployed to the battlefield. Their formation placed the heavy infantry in the center, with Roman cavalry on the right wing and allied cavalry on the left wing. In response, Hannibal deployed his forces in a similar formation, but placed his heavy infantry on the flanks and positioned his Gallic mercenaries in a concave, crescent-shaped formation in the center. He placed cavalry on both extreme wings.

 

3. The Roman Army's Initial Superiority

At the start of the battle, the Romans held the advantage. The Roman heavy infantry, which had already earned a fearsome reputation across the Mediterranean, charged directly at Hannibal's troops. Although the Gallic mercenaries put up a strong resistance, they began to be pushed back. Meanwhile, Hannibal's cavalry was dominating the cavalry skirmishes. The Gallic cavalry on Hannibal’s left wing, outnumbering the Roman right wing cavalry three to one, was gradually overpowering the Roman forces. The Roman right-wing cavalry fought back but eventually started to retreat. On the other hand, the Roman left-wing cavalry, commanded by Varro, fought well against the Numidian cavalry, which was roughly equal in size.

 

4. The Cavalry Clash

However, the cavalry engagements did not go in favor of the Romans. The 2,400 Roman right-wing cavalry were surrounded and eventually annihilated by the 6,000 cavalry of Hannibal’s forces. The Roman left-wing cavalry, too, were overwhelmed by Hannibal’s Numidian cavalry, who outmaneuvered them with superior horsemanship. Meanwhile, the Gallic mercenaries in the center, under pressure from the Roman heavy infantry, began to buckle. However, this was a trap. The retreat of the Roman cavalry and the deep penetration of their heavy infantry into Hannibal's lines exposed the Roman flanks. Hannibal’s heavy infantry, positioned on the wings, then struck the exposed Roman flanks, and his cavalry also attacked the Roman rear.

 

5. The Encirclement

This was Hannibal's strategy. Despite being outnumbered, he used his superior cavalry to complete a full encirclement. The Romans were trapped in a tight space, limiting their movements, and some were even crushed by the press of the surrounding forces. Only the soldiers on the outermost edges of the formation could fight, so the Roman army was unable to unleash its full combat potential. As Hannibal’s forces gradually closed in, the panicked Roman soldiers began to fall one by one, leading to near total annihilation.

 

6. The Outcome of the Battle

On that day, around 70,000 Roman soldiers were killed, and the 10,000 who had remained behind in camp were taken as prisoners. The Roman commander, Varro, managed to escape, but the serving consul, Aemilius, and former consul Servilius were killed, along with 80 senators. The Roman Senate had 300 members, meaning a quarter of them were lost in the battle. In contrast, Hannibal’s army lost about 5,500 men, most of whom were Gallic mercenaries. After the Battle of Cannae, which became a textbook example of encirclement warfare, no Roman general could match Hannibal’s skill, and Rome was left vulnerable to further devastation at his hands. In response, Rome resorted to a war of attrition, but it would take 15 years of hardship until Scipio’s appearance.