Tactics Used in the Battle of Cannae

Written by Lord Petru Sergeiescu. Originally Published in the Online Bird of Prey, Volume 4, Apr-Jun 2002.

Author’s note:

I initially decided to write this article for two reasons. The first was to bring forth a part of history that, while occurring well before the typical SCA time period of 600-1,600 AD, is an important piece of military knowledge. The second was to adapt the tactics used in the battle of Cannae into a useful strategy for our own mass combats. As I talked to others more knowledgeable than myself in the wonder and frustration of being an SCA commander, I opted to forego the second reason and concentrate on the history surrounding this battle between Hannibal’s Carthaginian army and Rome. This, hopefully, will not be too boring for you. I hope you enjoy reading this article as much as I thoroughly delighted in researching and writing it!

Petru Sergeiescu
tconn@ku.edu


Cannae: Hannibal’s Victory

The Roman Empire was growing in the third century BC. It continually expanded its borders, subjugating any whom stood in its path. Much of Europe was beginning to feel the impact of Rome’s continual thirst for land and power. When this expansion reached Africa, it ran across another country with a similar mindset. Carthage was, in its own right, a military and cultural powerhouse. Like many other cultures that encountered the Romans, it did not like the idea of being under Rome’s control. Unlike many others though, it could do something about the presence of Romans on Carthaginian soil.

The First Punic War was fought between 264-241 BC, with Carthage losing to the Romans, but retaining much of its sovereignty. The Second Punic War officially began when Hannibal landed on Italian soil. It should be noted that Hannibal was not out to conquer Rome. His mission was to “reduce the political power of Rome so that she should no longer be a constant menace to the prosperity, or even the continued existence of Carthage” (de Beer, 1969). To do this, Hannibal had to win enough battles and inflict enough damage to the Roman’s aura of invincibility that her city-states would rebel and/or defect from the Republic.

The pinnacle of Hannibal’s 15-year campaign on Italian soil was the battle of Cannae. The tactics Hannibal employed to defeat a superior Roman army have been studied and implemented throughout history. Prussian and German generals in WWI and WWII called decisive, complete victories ‘Cannaes’. General Norman Schwartzkopf, UN commander during the Gulf War, studied Cannae and employed the principles Hannibal used in his quick and highly successful attack against the Iraqi (Goldsworthy, 2000).

In order to fully appreciate the impact of Hannibal’s victory at Cannae, one must look at not only the tactics used during the battle, but the events that transpired both before and after Rome’s clash with the Carthaginians. This paper will briefly describe the events leading to, the fighting of, and the effects of Cannae on both Rome and Hannibal.

I. A Call to Arms

Hannibal was becoming a thorn in Rome’s side. Having already made his famous crossing of the Alps, Hannibal had battled his way deep into Italy. Successive victories at Ticinus and Trebia in 218 BC, followed by more decisive triumphs at the battles of Lake Trasimene and Volturnus in 217 BC had stirred the Roman Senate into taking immediate action. To make things worse, Hannibal’s army had escaped Dictator Quintus Fabius Maximus at Campania and settled in for the winter of 217/6 BC at the protective citadel at Gerunium.

In the early spring of 216 BC, Hannibal moved his troops south from Gerunium to the practically abandoned town of Cannae. This move served two purposes: To remove the threat of a possible Roman attack on Hannibal’s flank, and to provide his troops with much needed supplies (Peddie, 1997). Cannae was used as a granary by the Romans, and was the ideal location for Hannibal to replenish his food stores. The town itself was situated on a large, flat-topped hill that overlooked the plunder-rich Aufidus (Ofante) River plain. He was shadowed by a smaller Roman force led by Consuls Servilius Germinus and Atilius Regulus, who had assumed command after Fabius and Master of Horse Marcus Minucius Rufus were forced to relinquish their posts (Lazenby, 1978).

The Senate elected two Consuls to lead the army that would thwart Hannibal. The first, Gaius Terentius Varro, was by many accounts a hotheaded political placement. He was from a wealthy merchant family, and had risen through the political ranks by receiving the popular plebian vote. The second Consular appointment was made to directly oppose Varro’s election. Lucius Aemilius Paullus was a veteran commander of the First Punic War and was the patrician candidate put forth by ex-dictator Fabius. According to the historians Polybius and Livy, Paullus was a capable man who favored the Fabius defensive “wait and see” philosophy (Bradford, 1981).

The Roman army raised for these new consuls was the largest in the Republic’s history. While there is an argument among historians as to the exact number raised for the campaign of 216, the prevailing number tends to be eight legions of 5,000 men each. It was expected that Rome’s allies would match this number, bringing the total up to an astounding 80,000 men. The cavalry for this juggernaut was reported to be around 6,000 men, including allied support (Bradford, 1981).

Varro and Paullus departed Rome with their newly raised army and headed towards the army of Germinus and Regulus, already following Hannibal and heading towards Cannae. “The two Consuls took command on alternate days, in accordance with (Roman) custom” (de Beers, 1969). This was to be the army that would crush Hannibal and anyone else that got in its way. Rome’s might was in full view of the ancient world, and Varro and Paullus intended to show everyone exactly how nasty the legions could be when called upon to act.

II. Roman Soil Is Bloodied

After Varro and Paullus met up with Germinus and Regulus, they sent Regulus back to Rome, citing he was too old to campaign and fight (Caven, 1980). The now combined Roman forces marched towards Cannae. As they neared the now plundered town, Paullus noticed that the area was flat and open which heavily favored Hannibal’s superior cavalry. He recommended to Varro that they use the hill upon which Cannae sat as a defensible position, thus removing yet one more card from Hannibal’s deck of tactics. Varro, who commanded the Roman forces that day, disagreed and proceeded to advance the army onto the Aufidus plain. Hannibal harassed him with his light cavalry and skirmishers, but the Romans were able to successfully defend against them.

Meanwhile, Hannibal had moved his camp from the eastern side of the Aufidus to the west, where the ground was even flatter and more open. The next day, Paullus moved the main portion of his army across the river too, but left one-third of his army on the eastern bank to suppress pillaging and to collect water. The date was now late July. The heat was stifling, making water collection a necessity for both armies. The two armies stayed camped in their respective locations for two days; separated by a mere 1 1/2 miles. During the second of these two days (August 1), Hannibal offered battle. Paullus refused. Hannibal, who well understood the importance of the Aufidus’ water to the Roman troops, sent his Numidian cavalry to the smaller Roman camp to harass and kill any water-bearing slaves that were found outside protective fortifications. According to Polybius, the Numidians boldly rode up to the edge of the Roman encampment, causing havoc and thoroughly disrupting the supply of water to the Roman camp (Caven, 1980).

Varro was incensed, as Hannibal had hoped, and on August 2nd marshaled his forces and crossed back over the Aufidus to do battle. He positioned his 2,400 heavy Roman cavalry on the right flank, with the river to their right and the main body of the infantry to their left. On the left flank, approximately 3,600 Latin and allied cavalry were placed with their backs against the hill of Cannae, leaving their left and front sides open. Each Consul commanded one flank. Paullus took the heavy Roman right, while Varro oversaw the allied left. Germinus was given sole command of the largest Roman infantry ever assembled. Varro lined up his heavy infantry in a deep and relatively narrow phalanx formation that would limit their flexibility, but would increase their ability to “punch” a hole a thousand yards wide through the Carthaginian center (Goldsworthy, 2000; Caven, 1980). Goldsworthy (2000) noted that “the entire (Roman) army must have occupied a frontage of between one and two miles”. Ultimately, Varro’s plan was to have his cavalry units last long enough for the center of Hannibal’s army to break before the superior Roman infantry and then he would “mop up” the overpowered African infantry. This plan was used and almost succeeded in Trebia the previous year, but Hannibal’s elephants had thwarted Rome’s victory. Now, without elephants to save him, Varro believed Hannibal would fall before Rome’s might.

Hannibal crossed the river without incidence, using his light cavalry and light infantry to cover the main army’s river fording. He gave command of his roughly 7,000 heavy Spanish and Gallic cavalry to Hasdrubal, and lined them up against the Roman heavy cavalry. His right flank consisted of approximately 3,000 Numidian light cavalry, and was commanded by Maharbal. Much like the Mongols of later years, the Numidians were masters at hit-and-run cavalry tactics, relying on speed and confusion to be effective (Lazenby, 1978). They did not use bridles, but instead entwined their hands in their steed’s mane for control and guided their mounts with their knees.

Hannibal divided his 40,000 infantry into four sections. Roughly 5,000 Carthaginian veterans were placed on either side of the Gallic and Spanish infantry. Due to the successes Hannibal had attained in earlier battles, his African soldiers were outfitted in Roman armor, used Roman scuta, and fought with Roman swords. As was their custom, the Gauls were “naked” (most likely undressed to the waist), according to Polybius, while the Spanish were dressed in their typical white tunics bordered with purple. Both the Gauls and the Spanish had retained their own swords; the Gauls used long, slashing blades, while the Spanish preferred their short, stabbing swords (Goldsworthy, 2000). In all, there were approximately 20,000 Gauls and around 4,000 Spanish infantry deployed by Hannibal into the center of his formation. The fourth unit was comprised of about 6,000 light infantry (skirmishers), including Balaeric slingers and velites, which were used to test and harass the Romans before the battle began in earnest.

It should be noted at this point that there were several important factors involved in this battle besides number of troops. The first of these was hydration. Due to Hannibal’s guerrilla tactics on the smaller Roman encampment the previous day, a majority of the Roman legions and cavalry lacked proper hydration. That, combined with a hot August day in southern Italy and a brutal sun shining in their eyes as the afternoon wore on, would have severely affected performance. There was also a headwind with which the Roman troops had to deal. While the wind itself was not a major factor, the dust that Hannibal’s 50,000 men and horses created would have been enormous and potentially debilitating to sight. Experience was another crucial element in this battle. Hannibal’s men were veterans of at least two campaigns against the Romans. His African troops had been with him since he touched Italian soil. His Gallic, Spanish, and Numidian troops were fierce fighters that had been with him for at least one season of fighting. Rome’s levies were fresh troops. A majority was untested, thus increasing the need for quality leadership. That, coupled with such a large number of troops, played a factor in the events at Cannae. Finally, the terrain itself was advantageous to Hannibal. As mentioned earlier, the Aufidus plain was relatively flat and barren, giving a large advantage to Hannibal’s superior cavalry. Also, the Romans were in front of the hill leading to Cannae and hemmed in on their right flank by the Aufidus River, effectively leaving only their left flank as a viable retreat option (Bradford, 1981).

At the onset of the battle, the Roman and Carthaginian skirmishers began to pick at each other, testing for weaknesses and trying to force their opponent into committing to a plan of action (Lazenby, 1978). It wasn’t until Hannibal’s heavy cavalry charged the Roman right flank that the battle began in earnest. Hasdrubal’s 7,000 Spanish and Gallic heavy cavalry collided with Paullus’ 2,400 Italian heavy cavalry (Peddie, 1997). Immediately, the sheer force of numbers began driving the Romans back. To make matters worse, the river to their right and the infantry to their left effectively hemmed in the Romans. Many left their horses to fight on foot, allowing riderless horses to plunge unchecked through the Roman lines, causing further confusion (Lamb, 1960). The Romans were soon routed and began fleeing back towards their main camp and up the hill to Cannae. Hasdrubal successfully maintained command of his troops and rode behind the advancing Roman infantry and assisted the Numidians attack the Roman allied cavalry (de Beer, 1969).

On Rome’s left flank, Varro held his ground against the Numidian light cavalry. His troops did not ride after the fleet, shaggy mounts of the Africans, but instead braved their pulsing style of attack. Indeed, Varro was effectively and efficiently upholding his initial plan of having his cavalry withstand attack until his infantry could break the Carthaginian center. However, when Hasdrubal’s heavy cavalry threatened his right flank, Varro and his men rode with haste from the field. The Numidians gave chase while yet again Hasdrubal reformed his troops for attack (Lazenby, 1978).At the onset of the initial cavalry rush, the skirmishers for both sides melted back into their respective lines. The formation presented to the Romans was unique. Hannibal’s Gauls and Spanish troops were arrayed in a convex line, with the outermost point closest to the Roman legions. Intent on destroying their enemy, the Romans began their steady, tightly maintained march towards the Carthaginian forces. The Gauls and Spaniards fought valiantly, but had to give ground due to the sheer number of Roman troops. As they made their slow retreat, their line flexed backward from convex to straight, and then finally concave. Meanwhile, the impetus of the Roman’s forward advance carried them between the two African heavy infantry forces (Caven, 1980). Paullus, after the routing of his cavalry, assisted in leading the Romans towards their foe. As the front line of the Romans began to tire and meet continual resistance from the Gallic and Spanish troops, they realized they had nowhere to go for retreat. By that time, the Gauls and Spaniards had been pushed to the rear of their battle lines. They had yielded ground, but never broke before the Roman legions. The Roman advance slowly ground to a halt as those in front were stymied while those behind continually pressed forward.

At this time, Hannibal signaled the final stage of his battle plan. With the sound of war horns, the heavy African infantry wheeled towards each other and began attacking the Roman flanks (Caven, 1980). Meanwhile, the Gauls and Spaniards redoubled their efforts and applied pressure to the Italian front ranks. It was also at this time that Hasdrubal’s heavy cavalry crashed into the back of the Roman infantry, effectively sealing off any avenues of escape. As the Romans vainly sought to free themselves from this perfectly executed double envelopment, the battle turned into a massacre.

III. The Price of Failure

The number of dead at the battle is yet another debatable point among historians. Livy reported that Rome and her allies lost about 45,000 infantry and 2,700 cavalry, whereas Appian and Plutarch cited 50,000. Polybius maintained that Rome lost a combined total of 70,000 troops. Regardless of the actual total, Hannibal’s victory was impressive. He lost approximately 4,000 Gauls, 1,500 Spaniards and Africans, and 200 cavalry in the battle and managed to immediately capture 3,000 infantry and 1,500 cavalry. 12,800 surrendered the following day instead of trying to fight their way out of the two Roman camps (Lazenby, 1978).

On the other hand, Rome was devastated. Varro fled to the crossroads of Venusia. Paullus was lost in the infantry battle, as was Germinus. Marcus Minicius Rufus, Master of Horse during the previous years’ campaign was killed. Rome also lost two quaestors (high ranking officials who judged certain criminal cases), a majority of her military tribunes (29 of 48), and 80 senators (Goldsworthy, 2000). To put this in perspective, one can look at potentially the bloodiest of all modern wars: WWI. The losses at Cannae suffered over a few square miles equaled the first day of fighting on the Somme. This may not sound important, but the battle for the Somme was spread over a 16-mile front (Goldsworthy, 2000). More men were killed at Cannae than in all four months of the battle of Passchendaele in 1917 (Bradford, 1981), considered one of the bloodiest battles of the “War to End All Wars”.

Aside from the physical loss of nearly 12% of Rome’s available manpower in under three campaign seasons, she suffered an even more dire pain: loss of invincibility. After the debacle at Cannae, Rome effectively left everything south of the River Vulturnus to Hannibal’s army (see map). The southern states in the Roman Confederacy, of course, did not like the idea of being left alone with a foreign army on their soil. Arpi, Salapia, Herdonia, and Uzentum in Apulia declared for Hannibal, as did most of the towns in Lucania, and those in Bruttium that weren’t Greek. Several peoples pledged their loyalty to Hannibal at this time too. The Picentes from the region of Salernum, the Hirpini, and most of the Samnites all favored Hannibal. However, the most important ally Hannibal gained from his victory at Cannae was the city of Capua in Campania. This alliance would prove very beneficial for Hannibal later in his campaign against Rome (de Beer, 1969).

Cannae was Hannibal’s finest hour. Even though he had success against Rome for many years following Cannae, he was never able to repeat such an astounding victory. Cannae was important for several reasons. Beyond being a costly military setback for Rome, it showed that the Roman army was not invincible. It also proved to many cultures of the time that Rome could not protect its own lands, causing Rome to lose political power in the
Mediterranean. However, despite this loss Rome was able to eventually defeat Hannibal and Carthage, thus ending the Second Punic War. Many cultures fought Rome, even sacked her capitol, but never did Rome again  fare so poorly in one battle.

References

  • Bradford, E. (1981). Hannibal. London: Macmillan London Ltd.

  • Caven, B. (1980). Punic Wars. London: George Werdenfeld and Nicholson
    Ltd.

  • De Beer, Sir G. (1969). Hannibal: Challenging Rome’s Supremacy. New
    York: Viking Press, Inc.

  • Goldsworthy, A. (2000). The Punic Wars. London: Cassell and Company.

  • Koch, H.W. (1995). Medieval Warfare. Greenwich, CT: Brompton Books
    Corporation.

  • Lamb, H. (1960). Hannibal. New York: Bantam Books, Inc.

  • Lazenby, J.F. (1978). Hannibal’s War: A Military History of the Second Punic
    War. Warminster, England: Aris and Philips Ltd.

  • Peddie, J. (1997). Hannibal’s War. Phoenix Mill, England: Sutton Publishing
    Ltd.

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