This is part-2 of the History Battles Series. Part 1 was a Chinese surprise featuring the mighty Shang Kingdom Vs the passionate Zhou.
In Brief
The Battle of Cannae was key combat of the Second Punic War between the Roman Republic and Carthage, fought on 2 August 216 BC near the old village of Cannae in Apulia, southeast Italy. The Carthaginian army, led by Hannibal, surrounded and nearly demolished a larger Roman army under the consuls Lucius Aemilius Paullus and Gaius Terentius Varro. It is considered as one of the biggest tactical achievements in military history and one of the gravest defeats in Roman history.
The Build-Up
Soon after the start of the Second Punic War, Hannibal crossed into Italy by crossing the Pyrenees and the Alps during the summer and early autumn of 218 BC. He immediately won major victories over the Romans at Trebia and Lake Trasimene. After these losses, the Romans designated Quintus Fabius Maximus Verrucosus as a dictator to deal with the menace. Fabius used attrition warfare against Hannibal, cutting off his supply lines and dodging pitched battles. These tactics proved obnoxious with the Romans who, as they recovered from the shock of Hannibal’s victories, began to question the wisdom of the Fabian strategy, which had given the Carthaginian army a chance to regroup. The majority of Romans were eager to see a swift conclusion to the war. It was dreaded that, if Hannibal continued plundering Italy unopposed, Rome’s allies might defect to the Carthaginian side for self-preservation.
Early historians rarely give the precise dates for the events they describe; for example, Livy provides no explicit dates for any of the battles of the Second Punic War. However, Macrobius, citing the Roman annalist Quintus Claudius Quadrigarius, states the battle was fought ante Diem iii nones Sextilis, or 2 August.
Figures for troops involved in classical battles are often unreliable, and Cannae is no exception. They should be handled with caution, notably those for the Carthaginian side. The Carthaginian army was a blend of warriors from numerous regions and may have numbered between 40,000–50,000. Their infantry included an estimated 8,000 Libyans, 5,500 Gaetulian, 16,000 Gauls, mainly Boii and Insubres (8,000 were left at camp the day of battle) and 8,000 of numerous tribes of Hispania, including Iberians, Celtiberians, and Lusitanians. Hannibal’s cavalry also came from diverse backgrounds. He commanded 4,000 Numidian, 2,000 Iberian peninsular, 4,000 Gallic, and 450 Libyan-Phoenician cavalries. Finally, Hannibal had an auxiliary skirmisher contingent consisting of 1,000-2,000 Balearic slingers and 6,000 mixed-nationality javelinmen, possibly including Lusitanians too. The uniting part for the Carthaginian army was the individual tie each group had with Hannibal.
The Battle
As the armies pushed on one another, Hannibal gradually extended the center of his line, as Polybius explained: “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, to produce a crescent-shaped formation, the line of the flanking gatherings growing thinner as it was prolonged, his object being to engage the Africans as a reserve force and to begin the action with the Hispanics and Celts.” Polybius described the weak Carthaginian center as deployed in a crescent, curving out toward the Romans in the middle with the African troops on their flanks in echelon formation. It is believed that the purpose of this formation was to break the forward momentum of the Roman infantry and delay its advance before other developments allowed Hannibal to deploy his African infantry most efficiently. While the majority of historians feel that Hannibal’s action was intentional, some have called this account fanciful, and claim that the actions of the day represent either the natural curvature that occurs when a large front of infantry marches forward or the bending back of the Carthaginian center from the shock action of meeting the heavily massed Roman center.
The battle began with a fierce cavalry engagement on the flanks. Polybius described many of the Hispanic and Celtic horsemen facing the Romans descending due to the lack of space to fight on horseback and called the contest “barbaric” in the sense of its utter brutality. When the Carthaginian cavalry got the upper hand, they cut down their Roman enemies without giving quarter. On the other flank, the Numidians involved in a way that merely kept the Roman allied cavalry occupied. Hasdrubal kept his triumphant Hispanic and Gallic cavalry under control and did not chase the retreating Roman right wing. Instead, he led them to the other side of the field to attack the socii cavalry still fighting the Numidians. Assailed from both sides, the allied cavalry broke before Hasdrubal could charge into contact and the Numidians pursued them off the field.
While the Carthaginian cavalry was in the process of defeating the Roman horsemen, the masses of infantry on both sides advanced towards each other in the center of the field. The wind from the east blew dust in the Romans’ faces and obscured their vision. While the wind was not a major factor, the dust that both armies created would have been potentially debilitating to sight. Although it made seeing difficult, troops would still have been able to see others in the vicinity. The dust, however, was not the only psychological factor involved in the battle. Because of the somewhat distant battle location, both sides were forced to fight on little sleep. Another Roman disadvantage was thirst caused by Hannibal’s attack on the Roman encampment during the previous day. All of these psychological factors made battle especially difficult for the infantrymen.
The light infantry on both sides engaged in indecisive skirmishing, inflicting few casualties and quickly withdrawing through the ranks of their heavy infantry. As the Roman heavy infantry attacked, Hannibal stood with his men in the weak center and held them together in a controlled retreat. The crescent of Hispanic and Gallic troops buckled inwards as they gradually withdrew step by step. Knowing the superiority of the Roman infantry, Hannibal had instructed his infantry to withdraw deliberately, creating an even tighter semicircle around the attacking Roman forces. By doing so, he had turned the strength of the Roman infantry into a weakness. While the front ranks were gradually advancing, the bulk of the Roman troops began to lose their cohesion, as troops from the reserve lines advanced into the growing gaps. Soon they were compacted together so closely that they had little space to wield their weapons. In pressing so far forward in their desire to destroy the retreating and seemingly collapsing line of Hispanic and Gallic troops, the Romans had ignored (possibly due to the dust) the African troops that stood uncommitted on the projecting ends of this now-reversed crescent. This also gave the Carthaginian cavalry time to drive the Roman cavalry off on both flanks and attack the Roman center in the rear. The Roman infantry, now stripped of security on both its flanks, formed a wedge that drove deeper and deeper into the Carthaginian semicircle, driving itself into an alley formed by the African infantry on the wings. At this decisive point, Hannibal ordered his African infantry to turn inwards and advance against the Roman flanks, creating an encirclement in one of the earliest known examples of a pincer movement.
When the Carthaginian cavalry overwhelmed the Romans in the rear and the African flanking echelons assailed them on their right and left, the advance of the Roman infantry was brought to an abrupt halt. The Romans were henceforth embedded in a pocket with no means of escape. The Carthaginians created a wall and began to systematically massacre them. Polybius wrote: “as their outer ranks were continually cut down, and the survivors forced to pull back and huddle together, they were finally all killed where they stood.”
As Livy described, “So many thousands of Romans were dying… Some, whom their wounds, pinched by the morning cold, had roused, as they were rising, covered with blood, from the middle of the heaps of slain, were overpowered by the enemy. Some were found with their heads plunged into the earth, which they had unearthed; having thus, as it seemed, made pits for themselves, and having suffocated themselves.” Victor Davis Hanson claims that nearly six hundred legionaries were slaughtered each minute until darkness brought an end to the bloodletting. Only 14,000 Roman troops succeeded to escape, most of whom had cut their way through to the nearby town of Canusium.
Aftermath
For a short period, the Romans were in total disarray. Their best armies in the peninsula were destroyed, the few scraps severely demoralized, and the only surviving consul (Varro) completely discredited. As the story goes, Rome announced a national day of mourning as there was not a single person who was not either related to or familiarized with a person who had died. The Romans became so hopeless that they resorted to human sacrifice, twice burying people alive at the Forum of Rome and dropping an oversized baby in the Adriatic Sea (perhaps one of the last instances of human sacrifices by the Romans, apart from public executions of defeated enemies dedicated to Mars).
Source: Cambridge History, Wikipedia