On 2 August 216 BC, by the Roman calendar of the time, Hannibal's Carthaginian army met the largest force the Roman Republic had yet put into the field on the plain of the Aufidus river near Cannae, in Apulia. His center gave way on purpose, his African infantry closed on the Roman flanks and his cavalry struck their rear. The consul Lucius Aemilius Paullus was killed, and the ancient historians put the Roman dead at between about 48,000 (Livy) and 70,000 (Polybius). Cannae became the classic example of a double envelopment.
A date in the old Roman calendar
The day comes from the Roman annalist Claudius Quadrigarius, quoted by Aulus Gellius, who wrote that the slaughter at Cannae took place on the fourth day before the Nones of August, that is 2 August. That is a date in the Roman republican calendar, not the Julian one introduced much later, and the historian C. F. Konrad notes that the state of the calendar during the Second Punic War is still not fully settled: estimates of how far it ran ahead of the solar year range from none or two weeks to five or six. Britannica dates the battle simply to August 216 BC.1
The trap
Hannibal had been in Italy for two years when he seized the citadel of Cannae, where the Romans kept grain and supplies gathered from the country around. The senate decided to give battle and sent both consuls, Paullus and Gaius Terentius Varro, with some 80,000 infantry and about 6,000 cavalry, against Hannibal's roughly 40,000 foot and 10,000 horse. The consuls held command on alternate days, and Polybius writes that on the morning of the battle it was Varro's turn.2
Hannibal pushed his Gallic and Spanish infantry forward in a crescent, with his African troops held back on either side. The legions, drawn up much deeper than usual, drove the crescent back, but it bent without breaking and drew them in. The Africans then turned inward against both Roman flanks, while Hannibal's cavalry, having beaten the Roman horsemen on the wings, fell on the rear of the legions. Packed together and surrounded, the Romans were cut down where they stood.3
The death of a consul
Livy tells how Paullus, wounded early in the fighting by a sling stone, was found sitting on a rock covered in blood by the military tribune Gnaeus Lentulus, who offered him his horse; the consul refused, sent Lentulus to warn the senate to fortify Rome, and was killed by the enemy moments later. Britannica also records Paullus among the dead, with many senior officers. Varro escaped to Venusia with about seventy horsemen in Polybius's account and about fifty in Livy's.4
The losses are uncertain. Polybius puts the Roman dead at about 70,000, with some 10,000 more captured away from the battle line, and Hannibal's losses at about 4,000 Celts, 1,500 Spaniards and Africans and 200 cavalry. Livy gives 45,500 infantry and 2,700 cavalry killed. Britannica gives a range of 55,000 to 70,000 Roman dead and about 6,000 Carthaginian.5
Victory without the war
In Livy's famous scene, Hannibal's cavalry commander Maharbal urged an immediate march on Rome and, when Hannibal hesitated, told him that he knew how to win a victory but not how to use it. Rome refused to negotiate, went back to Fabius Maximus's strategy of avoiding pitched battle, and wore Hannibal down over the following years. The full story, with the armies, the commanders and the battlefield today, is in our article on the Battle of Cannae.6
