Battle of Cannae: 10 Things You Should Know


To put things into perspective, the Battle of Cannae (216 BC), contested between the ancient Mediterranean powerhouses of Rome and Carthage, is usually considered as a particularly bloody episode – which had (possibly) resulted in the highest loss of human life in a single day in any battle recorded in history. In terms of sheer numbers, the baleful day probably accounted for over 40,000 Roman deaths (the figure is put at 55,000 by Livy, and 70,000 by Polybius), which equated to about 80 percent of the Roman army fielded in the battle!

On a comparative note, the worst day in the history of the British Army usually pertains to the first day of the Battle of the Somme in 1916, where they lost around 20,000 men. But the male population of Rome in 216 BC is estimated to be around 400,000 (thus the Battle of Cannae possibly took away around 1/10th – 1/20th of Roman male population, considering there were also allied Italic casualties), while Britain had a population of around 41,608,791 (41 million) at the beginning of 1901, with half of them expected to be males.

1) Leadership Over Different Nationalities –


Alexander was known for his self-assurance, Hannibal for his personality. As referenced in the book Hannibal by Nic Fields, Livy attests to the latter’s leadership skills by mentioning how Hannibal managed to not only control his mercenary army (which had been described as ‘a hotch-potch of the riff-raff of all nationalities’) but went on to win victories over the Roman forces for fifteen straight years – and that too within the confines of Italy. The irony in this case related to how the same folks who fought for money and plunder, grouped together to forego such things in favor of innumerable hardships for their chosen leader. This certainly speaks highly of the potent charisma demonstrated by Hannibal all throughout these rigorous years spent in a foreign land.

However, beyond just charisma, there must have been a more intrinsic sensitive side to his ‘management skills’. Literary pieces of evidence point out how Hannibal slept alongside the ordinary soldiers out in the cold open; he even went hungry along with his soldiers when the supplies ran low. But more importantly, the soldiers (despite their different origins) placed their utmost trust on their Carthaginian commander when it came to actual battles. Simply put, they acknowledged and followed the directives of their general – mostly without question, due to their collective belief in the prodigal generalship of Hannibal

2) ‘Unity’ in Diversity –


While Hannibal’s leadership played a major role in reinforcing the psyche of the varied nationalities under his command, due credit shouldn’t be snatched away from his supporting officer corps. They played their crucial role in galvanizing a truly multinational force comprising both mercenaries and regular troops with their different backgrounds, societies and even fighting styles.

To that end, since we are talking about the nationalities, the ‘Carthaginian’ army that crossed over from the Alps, mostly consisted of African (including Liby-Phoenicians and Numidians), Iberian (including the Balearic islanders) and Celtic soldiers – with their vastly variant cultures being integrated into a nigh professional force that regularly triumphed over the more homogeneous Romans.

And intriguingly enough, Hannibal and his officers didn’t force any scope of uniformity on their ‘rag-tag’ army. On the contrary, the commanders expected each of the cultural domains to bring their own set of ‘native’ skills and expertise on the battlefield – thus resulting in the ultimate ‘counter’ army that could thrive in most tactical scenarios.

3) The ‘Pilum Fodder’

Illustration by Angus McBride.

In the earlier entry, we mentioned how the majority of Hannibal’s army was derived from North Africa, Iberia and Cisalpine Gaul (northern part of Italy inhabited by Celts since the 13th century BC). Among them, the latter was considered somewhat inferior, at least when it came to the scope of Cannae.

As a result, the Celts formed the bulk of the infantry that held the middle formations, and thus bore the brunt of the Roman juggernaut of maniples. Hannibal clearly knew that this Carthaginian position would incur a greater number of casualties, given the Roman penchant for advancing straight-on to the main enemy lines after discharging their deadly ‘pila‘ (javelins). But still the general took the gamble, and centrally positioned his expendable ‘pilum fodder’ Celts – an audacious tactical ploy that we will discuss later in the article.

Now the question arises – why was Hannibal’s evaluation of (most) Celtic soldiers seemingly so harsh? Well, part of it possibly had to do with the erratic political affiliations of many Celtic tribes in Cisalpine Gaul, many of whom proved to be unreliable during the course of the Second Punic War. As for the warfare side of affairs, while the well-armored Celtic cavalry forces (mostly derived from their nobles and retainers) were crucial to the success of some Carthaginian engagements in Italy, many of their Gaulish infantrymen counterparts were generally considered as an undisciplined bunch that favored individual bravery over group-based tactics.

These Celtic men were often armed with long slashing swords and protected by only oval, leather-covered shields; while few even went to battle entirely naked. Furthermore, we should also take note of how Hannibal’s initial army consisted of only the African and Spanish troops, while the Celts were recruited ‘later’ on the way to the Alps and beyond. So there might have been a strategic scenario in Cannae where Hannibal wanted to preserve his ‘core’ army of Spaniards and Africans (for future battles), while the rank-swelling yet ill-equipped Celts were given the task of directly facing their long-known adversaries – the Romans.

4) The ‘Slinging’ Advantage of Hannibal –


Beyond the conventional infantry forces of Hannibal, it was the light infantry that stood out in most of the encounters of the Second Punic War in Italy. In fact, Hannibal had deeply studied the Roman tendency of fielding organized ranks of maniples comprising what can be technically termed as heavy infantrymen, circa late 3rd century BC. As a result, the Roman battlefield tactic was spectacularly simple – as it often entailed countering the enemy forces (who were mostly disordered) with sheer discipline and rotation of manpower on the field itself.

Hannibal formulated a plan against these seemingly invulnerable formation-based armies by inducting highly trained light troops into the ‘rag-tag’ Carthaginian army, especially from Spain and Africa. One example would pertain to the incorporation of Balearic slingers who were known for their expertise in accuracy over various ranges (which encompassed the use of three different types of slings!). In fact, their effectiveness was so aptly demonstrated against the Romans that even conventional archers were eschewed in favor of these lightly armed mercenaries.

5) The Superior Cavalry Fielded by Carthaginians –

Numidian light horsemen armed with javelins.

And since we brought up the scope of effectiveness, very few units showcased their on-field efficacy against the tightly packed Romans as the Numidian riders armed with only javelins. Espousing daredevilry on horseback, they probably rode without reins – using just a rope around the horse’s neck and a small stick to give it commands. In many cases (like at the Battle of Trebbia), Hannibal utilized their nigh-perfected mobility and zig-zag maneuvering ability to draw the attention (and ire) of the Romans. Such skirmishing tactics, often mixed with vocal insults, in turn, forced the roused Roman to give battle even when they were under-prepared.

The light cavalrymen were accompanied by the ‘heavy’ variety of the aforementioned Celtic horsemen. Usually derived from their nobles and retainers, many of these cavalrymen were richly attired in expensive mail and helmets – and thus fulfilled the role of the pseudo-shock mounted troops (a task that was paramount in the Battle of Cannae).

Hannibal also fielded Spanish cavalry forces, who were mounted atop stout horses, but was armed in a similar fashion to their infantry counterparts – with short falcata swords and smaller spears. They mainly served as medium cavalry useful for sustaining the initial charges, while also being flexible enough for pursuing retreating enemy forces.

6) The Opposing Roman army at Cannae –

Starting from left – Hastati, Velites, Triarii and Principes.

The greatest strength of the Roman army had always been its adaptability and sense of evolution. So by the time of the first Samnite War (in around 343 BC), the Roman army seemed to have endorsed newer formations that were more flexible in nature, as opposed to their initial hoplite-based tactics. This change in battlefield stratagem was probably in response to the Samnite armies – and as a result, the maniple formations came into existence (instead of the earlier rigid phalanx).

In that regard, the very term manipulus means ‘a handful’, and thus its early standard pertained to a pole with a handful of hay placed around it. According to most literary pieces of evidence, the Roman army was now divided up into three separate battle-lines, with the first line comprising the young (and somewhat lightly armored) hastati in ten maniples (each of 120 men); the second line comprising the hardened principes in ten maniples; and the third and last line consisting of the veteran triarii in ten maniples – who probably still fought as heavy hoplites (but their maniples only had 60 men).

Additionally, the battle-lines were possibly screened by the light-armed velites, who mostly belonged to the poorer class of Roman civilians, and were also flanked by the equites – cavalrymen who came from higher economic backgrounds. Thus a single legion combined 30 such maniples (of three classes of infantrymen), along with velites and equites, thus roughly equating to around 5,000 men.

Unfortunately, for the Romans, the equites were not up to the mark of their Carthaginian counterparts; and usually comprised a smaller percentage of the army when compared to other ancient powers. Furthermore, in an odd turn of events, a 10,000 strong force of triarii didn’t take part in the Battle of Cannae, since these men were chosen to guard the strategic Roman camp at one end of the battle zone by the River Aufidius (Ofanto).

As for the scope of conscription, The citizen militia (or soldiers) of Republican Rome were levied and then assembled in the Capitol on the day that was proclaimed by the Consuls in their edictum. This process was known as dilectus, and interestingly the men volunteers were arranged in terms of their similar heights and age. This brought orderliness in terms of physical appearance, while similar equipment (if not uniform) made the organized soldiers look even more ‘homogeneous’.

The Roman army recruits also had to swear an oath of obedience, which was known as sacramentum dicere. This symbolically bound them with the Roman state, their commander, and more importantly to their fellow comrades-in-arms. In terms of historical tradition, this oath was only formalized before the commencement of the Battle of Cannae, to uphold the faltering morale of the Hannibal-afflicted Roman army. According to Livy, the oath went somewhat like this – “Never to leave the ranks because of fear or to run away, but only to retrieve or grab a weapon, to kill an enemy or to rescue a comrade.”

7) Cannae Chosen For Provocation –


In the opening paragraph, we mentioned how the burgeoning Roman realm suffered one of its greatest military disasters at the Battle of Cannae. However, objectively beyond just baleful numbers, the encounter in itself was a set-piece triumph for Hannibal, with the general’s strategy even dictating the very choice of the battle itself (as referenced in Cannae 216 BC: Hannibal Smashes Rome’s Army By Mark Healy).

Cannae and its ruined citadel had long been used as a food magazine by the Romans with provisions for grain oil and other crucial items. Hannibal knew about this supply scope and willfully made his army march towards Cannae (in June, 216 BC) for over 120 km from their original winter quarters at Gerunium.

Interestingly enough, the camp of the Carthaginian army was just set above verdant agricultural fields with ripening crops – which could provide easy foraging to the snugly quartered troops. In other words, the chosen location and its advantages surely drummed up the morale of these soldiers, while strengthening their resolve and dedication for their commander.

However, at the same time, there was a more cunning side to Hannibal’s choice of Cannae – (possibly) unbeknownst to his army. That is because Rome was still dependent on the grain cultivated in native Italy (while seeking alternative corn supplies from Sicily), especially from the region of Apulia where Cannae was located. Simply put, the choice of Cannae was an intentional ploy to provoke the Romans to give direct battle – as opposed to the Fabian strategy of delaying. This once again alludes to Hannibal’s confidence and craftiness when it came to military affairs and logistics.

8) The Convex-Crescent –


Choosing the battle was not enough for the great Carthaginian general; Hannibal proceeded on to array his entire army* (of 35,000 – 40,000 infantrymen and around 10,000 cavalry) into ‘tailored’ formations that were dedicated to countering the superb infantry quality and numerical advantage of Romans, who had probably fielded somewhere between 50,000 – 63,000 infantrymen* (along with around 6,400 cavalry – combining both the Romans and allied forces).

Now it should be noted that among these 35,000 infantrymen under Hannibal’s command at Cannae, the ‘crack’ experienced soldiers from Africa and Iberia – who had originally crossed the Alps, only numbered around 14,000 men. Thus the remaining bulk of the infantry comprised the Celts and other assorted lightly-armed troops. As for Carthaginian cavalry forces, the seasoned Spaniards and Numidians formed the majority of 6,000 horsemen, while the remaining 4,000 were formed by the ‘elite’ Celtic cavalry derived from their nobles and retainers.

Now one of the first counter-measures of Hannibal at the Battle of Cannae was to put his ‘heavy’ cavalry forces (of Celts and Spaniards) on the left flank, to directly oppose (and clear out) the Roman cavalry under consul Lucius Aemilius Paullus. On the right flank, the Numidians were deployed and expected to carry out their unorthodox style of luring in the Roman-allied cavalry forces and then dispatching them with well-timed javelin throws.

But the biggest surprise came from the infantry formations of Hannibal. Instead of opting for the traditionally strong center, the Carthaginian general deliberately arrayed his most ‘expendable’ Celtic soldiers along the middle portion, and they were complemented by alternate companies of Spanish and Celtic soldiers in the successive flanks.

Finally, the two ‘hidden’ wings of the infantry were filled by the heavy African troops (Liby-Phoenicians) who were possibly attired in ‘Roman’ style, with armors that were stripped off the dead Roman soldiers in the previous encounters. As for their tactics, some historians have talked about how these crack troops adopted the phalanx formation – though we are still not sure of their exact maneuvers.

After arranging his entire line, Hannibal commanded his central body of troops to slightly move forward while keeping their links with their successive flanks. As a result, a convex-crescent of formations emerged from the Carthaginian side (showcased in the image above), with the two wings thinning out and covering the heavy African troops.

9) The Tactical Trap –


By the time the massed Roman columns (which were kept deeper, thus reducing their width) reached the Carthaginian lines, Hannibal’s heavy cavalry forces on the left flank (headed by Hasdrubal) had already pushed back the main Roman cavalry force commanded by their consul. As a matter of fact, Aemilius Paullus was himself injured by a sling-shot and thus had to dismount – thus dealing a crippling blow to the morale of the proximate Roman soldiers.

This allowed a gap to emerge on this side, and Hasdrubal took advantage of the retreating enemy to push through the momentary disconnect between the Roman cavalry and infantry lines on the left. He expertly traversed the ‘gap’ and wheeled around his fresh cavalry forces to meet the Roman infantry lines at their unguarded rear positions.

On the other flank (right), the Numidians were successful in disrupting the Roman allied cavalry forces under the other consul Gaius Terentius Varro. They did so by their idiosyncratic fighting methods of zig-zag maneuvering and false retreats. Finally, a fresh detachment of heavy cavalry from the left joined their Numidian comrades, and together they successfully chased away the panicked Roman allied cavalrymen off the field.

However, in spite of the reversals of their cavalry forces, the main Roman infantry lines maintained their cohesion and pushed forth the ‘weak’ Carthaginian center with aplomb. The previously convex-crescent had now bulged ‘ backward’ into a concave with the disciplined Roman legions making short work of their mostly Celtic adversaries.

But therein laid the audacious tactical trap sprung by Hannibal. That is because as the Romans pushed further in, they were met with alternate companies of Celtic and Spanish forces – soldiers who operated in distinct styles of warfare, with the boisterous Celts using their long slashing swords and the deft Spaniards using their short stabbing swords. This alluded to a confusing set of tactics to counter for the legions since they had to continually adapt to the ‘changing’ nature of the enemy – thus limiting their progression while exacerbating their fatigue levels.

Finally, when the concave had ‘bulged’ sufficiently, Hannibal commanded his crack African troops from the hidden wings to join in the fray; and these (possible) phalanxes plunged deep into the tattering Roman flanks. The ‘coup de grace’ was then dealt by the Hasdrubal’s wheeling cavalry – as they struck the rear lines of the Roman infantry, thus completely surrounding the enemy inside a rough circle.

By this time the Romans were so pressed for space that many of them didn’t even have room for swinging their swords. The end result of the Battle of Cannae, according to Livy, amounted to around 50,000 Roman deaths (though modern estimates put down this figure to around 40,000) and 20,000 prisoners, while the Carthaginians suffered only 8,000 casualties.

10) The Paradox of Cannae –


Interestingly enough, it was the Battle of Cannae that was ultimately responsible for Hannibal’s unceremonious call back to Carthage (in 203 BC) after 15 years of remaining undefeated on Italian soil. In the post years of the Cannae incident, the Roman leadership came to a realization that they couldn’t counter Hannibal’s genius in conventional warfare.

As a result, they reverted to the defensive Fabian strategy (named after Quintus Fabius Maximus Verrucosus) which basically entailed a guerrilla-warfare type scenario with internal lines of communications. In other words, the Romans rigorously avoided open-field battles, while resorting to hit-and-run and harassing tactics that afflicted the stretched Carthaginian lines and patrols who were regularly dispatched for foraging.

This predicament was further exacerbated when Hannibal had to provide garrisons for the newly defected cities in the south of Italy. This took away much of his precious manpower that had already deteriorated due to previous battles, skirmishes, and attrition. Moreover, since much of Hannibal’s army was composed of mercenaries of different nationalities – they were neither suited to siege warfare or garrison duty, and thus many of them started to desert en masse.

So slowly but surely, the once grand expeditionary force that made its way to Italy via the Alps, was now only a shadow of itself. By 203 BC, even chances of arriving reinforcements from Carthage or Iberia went slim, with both of his brothers being soundly defeated. And ultimately, Hannibal himself had to answer the desperate call from his own Barcid war party, which was one of the two major political factions of Carthage. Consequently, the general and some of his trusted mercenaries finally decided to set sail for Africa. And thus ended the epoch of Hannibal in Italy – paradoxically brought on by his incredible victory at the Battle of Cannae.

Honorable Mention – Gisgo’s Fear and Hannibal’s Retort


In the previous entries, we talked about the massive number of casualties suffered by the Romans at the Battle of Cannae. This automatically suggests the huge number of troops actually fielded by both the armies – with estimations of around 70,000 Romans and 45,000 Hannibal-commanded soldiers taking part in the encounter (though some modern conjectures tend to lower these figures).

Given such an enormous scale of the impending battle and the size of the approaching Roman army, many of the Carthaginian officers were clearly anxious about their numerical inferiority. One such officer named Gisgo even went ahead and voiced his uneasiness to Hannibal at the sight of the Romans (who were moving forward in tighter formations with greater manipular depths than usual).

And this is where Hannibal’s greatest strength was revealed, and it pertained to his character. Instead of punishing or even rebuking Gisgo for such a demoralizing comment – especially before a battle, the general turned to the officer and perkily commented – ‘There is one more thing you have not noticed.’ When Gisgo asked, ‘What is that sir?’; Hannibal replied, ‘In all that great number of men opposite there is not a single one whose name is Gisgo.’ The nearby batch of officers wholeheartedly laughed with Hannibal’s retort – and the ‘infectious smiles’ were carried forth by even the rank-and-file soldiers, thus calming their nerves.

Note* – The numbers mentioned in the article shouldn’t be considered as exactly accurate figures, but rather as estimated figures – compiled from both ancient sources and modern hypotheses.

Book References: Cannae 216 BC: Hannibal Smashes Rome’s Army (By Mark Healy) / Hannibal (by Nic Fields) / The Punic Wars (By Brian Caven) / Cannae: Hannibal’s Greatest Victory (By Adrian Goldsworthy)

Online Sources: Ancient Encyclopedia / UNRV / / Livy’s Account (

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