The Battle of Cannae, an historic and decisive battle of the Second Punic War, took place on August 2, 216 BC between the Punic army, led by Hannibal Barca, and Roman troops, commanded by consuls Gaius Terentius Varro and Lucius Aemilius Paullus.
The battle took place in the city of Cannae in the Apulian region to the southeast of the Italian Peninsula, and ended with the victory of the Carthaginian army, despite being clearly outnumbered by the Romans. After the Roman defeat, several city-states abandoned the Roman Republic side.
Although the battle didn´t bring the Carthaginians final victory in the Punic War, it is nevertheless remembered as one of the most incredible battles in military history, and the biggest defeat of Roman history up until that moment, though the future would deliver similar disasters.
After recovering from the losses of previous battles (the Battle of Trebia and the Battle of Lake Trasimene), the Romans decided to confront Hannibal in Cannae, with 87,000 soldiers and allies. With their right wing deployed along River Aufidus, the Romans placed their cavalry at the flanks and grouped their heavy infantry at the centre, in a deeper formation than usual. In order to counterbalance the Roman formation, Hannibal used a pincer tactic, in which he placed his less reliable infantry in the centre and positioned the Carthaginian cavalry to the opposite flanks. His lines adopted a crescent shape, while his veteran troops advanced from the sides.
While the armies advanced to confront each other, Hannibal gradually extended the central part of his line. As Polybius wrote:
“After thus drawing up his whole army in a straight line, he took the central companies of Hispanics and Celts and advanced with them, keeping the rest of them in contact with these companies, but gradually falling off, so as to produce a crescent-shaped formation, the line of the flanking companies growing thinner as it was prolonged, his object being to employ the Africans as a reserve force and to begin the action with the Hispanics and Celts.”
Some historiographers say that the curvature of the Carthaginian army was probably caused by its own natural reaction to the advance at the centre by the heavy Roman infantry.
When both armies met, Hannibal launched a fierce cavalry attack. Polybius described many of the Hispanic and Celtic horsemen facing the Romans dismounting due to the lack of space to fight on horseback, and called the struggle “barbaric” in the sense of its utter brutality. The Carthaginians also disposed a line of 800 Balearic slingers, who were famous for their accuracy, to cast stones or bullets. They nevertheless were unsuccessful in stopping the Roman advance, and a rain of spears from both sides followed. After this, hand-to-hand combat started.
Hannibal was with his men in the fragile centre of his formation, and had them move in a controlled retrieval. Knowing the superiority of the Roman infantry, Hannibal created a semicircle that grew thinner and thinner, but surrounded the Roman forces. Romans had not only started to lose cohesion at the centre, but also had failed in their intent to break the line of Hispanic and Gallic troops. Fatally, they had also ignored the advance of the African troops at the ends of the Carthaginian formation.
The Carthaginian cavalry managed to defeat the Roman cavalry from the flanks, and had freedom to charge against the centre of the Roman formation from the rearguard. The Romans were trapped, with no way out.