Cannae, 2 August 216 BC

The battle, stage by stage

1. 2 August 216 BC (Roman calendar), dawn

   Crossing the Aufidus

   For days the two armies have faced each other on the plain of the Aufidus (the modern Ofanto), near the little hill-town of Cannae, whose citadel Hannibal has seized as a supply depot. The Romans have two camps, a larger one on the left bank and a smaller one across the river; Hannibal's camp is on the same bank as the larger Roman camp, possibly near modern San Ferdinando di Puglia. The consuls command on alternate days, and on this day it is Gaius Terentius Varro's turn. At first light he leads the troops of the larger camp across the river and draws them up with those from the smaller camp, leaving about 10,000 men behind. Hannibal sends his slingers and spearmen across, then crosses with the rest at two places. Where exactly this happened is disputed. This map follows Peter Connolly and Adrian Goldsworthy: the right bank, on a plain north of the Cannae hills, with the river then running further north than it does today. Every position is conjectural.

2. Early morning

   The lines drawn up

   Polybius has the Roman line facing south, its right flank on the river; here it is set slightly at an angle across a plain about 2 km wide, between the river and the hills round Cannae. About 2,400 Roman cavalry stand by the water under Lucius Aemilius Paullus. Then come the legions and allied infantry, some 80,000 foot in Polybius's figures, with the maniples set closer together than usual and the formation many times deeper than it is wide. On the left, under Varro, the allied cavalry reach toward the high ground. Opposite, Hannibal puts his Spanish and Gallic heavy cavalry under Hasdrubal by the river and the Numidian horse on his right. African heavy infantry stand in deep blocks on both wings, and in the centre are Gauls and Spaniards in alternate companies, pushed forward in a bow-shaped crescent. He and his brother Mago stay with the centre. Ancient figures give Hannibal about 40,000 foot and 10,000 horse; modern historians usually put the Roman army at 50,000–86,000.

3. Morning

   Hasdrubal routs the Roman horse

   After the light troops skirmish and fall back, the fighting begins by the river. There is no room to manoeuvre between the water and the infantry, and by Polybius's account the horsemen dismount and fight on foot. Hasdrubal's heavier and more numerous cavalry cut the Roman horse to pieces. Paullus, by Livy's account badly hurt by a sling-stone early in the battle, joins the legions. The Roman foot advance into the crescent; on the far wing the Numidians and the allied cavalry skirmish without decision. Meanwhile the garrison of the larger Roman camp, on orders, attacks Hannibal's camp across the river.

4. Late morning

   The crescent bends back

   The Gauls and Spaniards give ground slowly under the weight of the Roman mass, and the crescent bows backward until it is hollow. Pressing after the retreating centre, the Romans crowd inward and forward into the pocket. Now the African infantry, fresh and drawn up on both wings, turn inward and attack the flanks of the Roman column, which is packed too tightly for the rear ranks to fight. Behind the Roman army, Hasdrubal rides round from the river to join the Numidians, and the allied cavalry, seeing his squadrons coming, break before they are reached.

5. Midday

   The encirclement

   Leaving the Numidians to pursue the fleeing allied horse, Hasdrubal turns his cavalry against the rear of the Roman infantry. Varro escapes with the allied cavalry and reaches Venusia with a few riders. The Romans are now enclosed: Gauls and Spaniards in front, Africans on both flanks, cavalry behind. The sources make the shape of this envelopment clear; the distances drawn here are schematic.

6. Afternoon

   The slaughter

   Surrounded and compressed, the Roman army is cut down where it stands, and the fighting goes on for hours as the ring closes. Paullus is killed in the melee, and, by Livy's account, so are both consuls of the previous year and some eighty men of senatorial rank. Hannibal's own losses are put at about 5,700 by Polybius, most of them Gauls, and about 8,000 by Livy.

7. Evening, 2 August, and the next day

   Survivors and the camps

   By Polybius's count about 70,000 Romans and allies are killed and about 10,000 captured. Livy gives 45,500 infantry and 2,700 cavalry killed, with thousands more taken on the field and in the camps. Survivors make for the camps and the village of Cannae: 7,000 reach the smaller camp, 10,000 the larger and about 2,000 the village, by Livy's account, where Hannibal's cavalry under Carthalo rounds them up. The camp garrison, beaten back from Hannibal's camp, surrenders, and the camps give up the next day, though some men break out. About 4,000 foot and 200 horse reportedly reach Canusium (modern Canosa, some 11 km up-river), where the young Publius Cornelius Scipio and Appius Claudius rally them. The camps and the escape route are placed by conjecture.