On a sweltering August 2nd, the battle standard
in front of Varro’s tent signalled to the troops to array for battle. As the gusts of south-westerly Volturnus wind
raised clouds of fine dust across the dry Apulian soil, for the next several hours,
army officers closely supervised the complex deployment to ensure that the legions would
form in the correct order. Varro, and the rest of the Roman leadership,
decided to show the enemy their willingness to fight. However, they had no way of knowing if the
Carthaginians would accept a battle in this new location. But then...
Hannibal led his troops through the gates... The two armies crossed the river Aufidius
at various points and marched onto the dust-blown flat plain below the town of Cannae. Yet, the Romans still weren’t sure that
Hannibal would give battle, so they left a 10,000 strong garrison in the main camp. It was Paullus who insisted on this, arguing
that, besides guarding the baggage, this force could also threaten Hannibal’s camp and
cut off his line of retreat once the battle went in favour of the Romans. However, Hannibal wasted no time in deploying
his army, sending out his light troops to form a protective screen for the main body. Varro too sent out the velites to mask the
process of deployment from the enemy. There are suggestions that the Roman leadership
didn’t actually expect the more mobile Carthaginians to fight on such a narrow and confined battlefield,
and merely wanted to deploy the legions in front of the enemy to boost morale and rebuild
their confidence, after being humiliated the day before for refusing to fight. Such practices of building up the confidence
of the men were common in the battles of this period, but it is far more probable that the
Romans did, in fact, fully intend to fight this battle on the ground of their own choosing. Whatever the case, Hannibal is said to have
had 40,000 infantry and 10,000 horse, while the Romans fielded around 70,000 infantry
and 6,400 cavalry. Varro placed a screen of around 15,000 velites
in front of the main line. 4,000 allied horse were positioned on the
left under his direct command, while Paullus was in charge of the 2,400 Roman cavalry deployed
on the right. To compensate for their numerical inferiority,
the squadrons of horsemen were packed in a tighter formation, with no more than 1.5m
between each rider. Room to maneuver the horses wasn’t necessary
as their role would be purely defensive while the infantry drove the attack forward. Regular Roman infantry was mixed with the
cavalry to give more stability to the static squadrons. Servilius commanded the 55,000 Roman legionaries
and allied troops in the center, arrayed in a much deeper and more tightly packed triplex
acies. Varro used the overstrength maniples to add
depth to the infantry formations. Furthermore, he reduced the gaps between the
lines to bring the full weight of the legions to bear, aiming to overwhelm the enemy. He knew that, at Trasimene, the Roman heavy
infantry held off the Carthaginians for hours, inflicting significant losses, despite being
in an unfavourable position. And the year prior to that at Trebia, the
legions hacked their way through the Carthaginian center, getting the better of both the Gauls
and several contingents of Libyans, Hannibal’s best infantry. It’s worth noting that the tighter maniple
formations restricted the tactical flexibility, but eased the coordination of the massive
army and, more importantly, the deeper formations possessed longer endurance in a direct confrontation,
thus the Roman leadership was confident that the legions can outmatch the enemy and crush
Hannibal’s center yet again. To achieve this Varro chose the battlefield
wisely. He packed the legions on a narrow front, with
the river and the hills near Cannae protecting the flanks from envelopment. This would force the Carthaginian horsemen
into a frontal charge and the Roman cavalry was tasked with delaying long enough for the
legions to finish the job. If they could break through the Punic center,
it wouldn’t matter if the weaker Roman horse lost the fight on the wings, because at that
point the Carthaginian cavalry couldn’t do much more than harass the large block of
legions. The selection of the battleground at Cannae
could allow the heavy infantry to smash their Punic enemy. We do not know if Varro alone planned this
or if he was assisted by Paullus, Servilius and other members of the Roman leadership. The Roman plan was simple, but efficient. Meanwhile, Hannibal placed around 6,000 Spanish
skirmishers and up to 2000 renowned Balearic slingers as a screening force in front of
the army, instructing them to raise as much dust as possible to hide the disposition of
the troops. Behind them formed the close order infantry,
with 21,000 Gallic warriors making up the bulk of the main line. 3,000 veteran Spanish infantry were interspersed
to strengthen the center. But, unlike at Trebia, where his main line
collapsed because he amassed all of his infantry to try and match the Romans and didn’t keep
any reserves for decisive action and to plug the gaps in the line, this time he positioned
the 8,000 Libyans, his best, most disciplined men, in the rear, hiding them from view behind
the formations in the front. On the Punic right were 4,000 Numidian horsemen,
commanded by Hanno, tasked with holding the flank, while on the opposite side the Carthaginian
general placed 2,000 Spanish and 4,000 Gallic cavalry, under the command of Hasdrubal, planning
to overload the left flank in a direct attack on the Roman right, hoping to smash the enemy
cavalry and threaten the legions from the rear. Neither side was intimidated by the other. Gallic and Spanish troops had the confidence
of past victories against the legions, while the Romans trusted in their superior numbers,
remembering that even in prior defeats, their heavy infantry often prevailed in hand to
hand combat against the Punic troops. Then… around mid-day, like a lumbering beast,
the Roman formation moved forward! The Carthaginian cavalry on the left led the
line, trotting at pace, while the light infantry of both armies moved ahead of the main lines
to open the engagement. Now, hidden behind the dust raised by the
screen of skirmishers, Hannibal made his move, advancing with the main line to form a crescent
formation that would bulge towards the enemy. He understood that the Romans chose this narrow
battlefield to deploy their army as a battering ram and that his outnumbered infantry stood
no chance of stopping the legions if they tried matching them man for man. Therefore, the bulged line was supposed to
absorb the attack and then slowly retreat, to buy time until the cavalry attack on the
left unfolded. Hannibal personally commanded the troops in
the center, with the help of his youngest brother Mago, for these troops would bear
the brunt of the Roman assault and it was vital that they held out as long as possible. As the skirmishing between the light troops
began in the middle of the field, Carthaginian riders on the left advanced full tilt towards
the Roman citizen-cavalry. With veteran officers leading the way, the
Spanish and Gallic squadrons stayed compact, doubling up on and dispersing the first lines
of Roman horsemen, quickly penetrating their formation. Some of the Roman riders dismounted to fight
on foot, but the Carthaginians swarmed their positions, dragging their opponents from their
seats. But despite outnumbering the Romans 3 to 1,
the confined space largely negated the numerical advantage of the Punic riders and Hasdrubal
did well to tightly control his men, managing to overwhelm the Romans in a brief furious
charge. The Roman cavalry couldn’t cope and most
of them broke and fled, with the Carthaginians now in hot pursuit. Others huddled together to hold off the Punic
onslaught for as long as possible. Paullus himself escaped the carnage with his
retinue and moved to rejoin the fighting in the center. Meanwhile, on the opposite flank, the Numidians
pinned down the allied Italian cavalry with hit and run attacks, with neither side able
to gain an advantage. In the center, after a long exchange of projectiles,
the skirmishers retreated behind the close order infantry as the Roman legions closed
in. The massed ranks of legionaries must’ve
been an intimidating sight, advancing slowly while clashing their weapons against the wooden
shields, whilst the trumpeters added to the cacophony of noise. As an almost solid mass of rank upon rank
of armoured legionaries clashed with the enemy, Hannibal’s advanced center narrowed the
width of the initial contact, reducing the deadly momentum of the Roman attack. The bare chested Gauls, hacking at the enemy
with their long slashing swords, and the Spanish in their white tunics, thrusting forward with
their short blades, stood firm and held back the enemy for a time, but as more Roman troops
entered the fray, the weight of the legions drove back the mixed Punic formation. Roman velites supported the attack, while
the Carthaginian light footmen were ordered to reinforce the flanks of the infantry. Hannibal and his officers barked orders at
the men, telling them to stand off the Roman assault and slowly move back! Already overwhelmed by the wall of scutum
shields pushing them back, ordering the troops to retreat further in the face of the enemy
was fraught with risks. All it would take is a few men buckling under
pressure to cause slight cracks in the line that could quickly break the formation and
turn into a rout. But the Carthaginian general and his Punic
captains led from the front, fighting alongside the troops in the first lines, encouraging
the men to hold their nerve, carefully controlling their withdrawal! Hannibal knew that he had to stay in the fight
and buy time until events elsewhere on the field unfolded. And for now, the line held… Close to the hills on the right, the light
Numidian horsemen fought in small groups, throwing their javelins and rapidly retreating
before the enemy could pin them down. However, their attacks caused very little
damage, and Varro simply remained in place, making no effort to drive them back. The main role of the Roman cavalry was to
prevent the enemy from flanking the infantry formation long enough, until the main assault
of the legions broke through the center. But, on the other flank, the superior Carthaginian
horse have by now decimated the Roman cavalry, completely routing them from the field. Next, Hasdrubal could move against the rear
of the Roman center or help surround Varro’s allied cavalry on the right. But first, he had to regroup and allow his
men and horses time to rest, who were by now exhausted from pursuing the fleeing enemy
cavalry. Back in the center, as the Carthaginian infantry
fell back before them, the Romans pressed on, prodding and cutting through the retreating
enemy line. Sword in hand, the centurions and tribunes
shouted orders through the deafening noise of the screams and the clattering of weapons,
urging the maniples to charge together, sending more and more men into the concaved Punic
center, which seemed like it will soon break. Conversely, Hannibal and Mago pushed the men
to resist a while longer, trying to gain every precious second, hoping that the Spanish and
Gallic cavalry will come to their aid. But as more and more legionaries were drawn
inwards, the Roman breakthrough was inevitable and the pressure on the center finally broke
the Punic line! The Gauls and Spanish at first moved back
facing the enemy, with flurries of fighting still occurring, but before long they turned
and routed. With the enemy now on the run, Paullus and
Servilius poured more men into the gap, refusing to give the Carthaginians any chance to rally
and reform their lines. The overcrowded Roman center surged forward
into the salient! Hannibal’s infantry on either side of the
gaping hole managed to maintain their lines, but were nevertheless forced to retreat in
good order. Meanwhile, up the field, Hasdrubal had reformed
his squadrons and charged at Varro’s formation, realizing that he could not move against the
legions in the center before the threat of Roman cavalry was removed. Until now, Varro successfully held the flank,
but seeing the incoming Carthaginians, the Consul knew that the Roman cavalry on the
other wing must’ve routed, and he could not see what was going on in the center. Unsure if the day was lost and facing annihilation
himself against a force three times his own, Varro fled the field. The Numidians gave chase, while Hasdrubal
once again had to stop to rest and reform his cavalry, before he could turn them towards
the rear of the Roman infantry. Back in the center, legionaries in their tens
of thousands pressed forward to complete the rout of the enemy. As they advanced into the gap, the maniples
lost all cohesion, turning into a disorganized mob that rushed forward, with their officers
barely able to control small groups of men in their own immediate vicinity. This mattered little, however, as the Romans
could taste victory, having punched straight through the enemy’s center. Hannibal relied on trickery and ruse in his
prior victories, but it now seemed that the clear field at Cannae offered no possibility
for him to set up an ambush. But… as the mass of Romans streamed forward,
they found themselves between the columns of Libyan infantry, that moved against the
pursuing troops. Incredibly, the Carthaginian general outwitted
the Romans, yet again. By carefully masking the position of the Libyans
behind his troops in the front and using the clouds of dust raised by the fighting, Hannibal
concealed his best infantry from the enemy on an open field , luring the greatest army
Rome has ever assembled into an ambush set in plain view, in effect letting the legions
outflank themselves. As the Libyans pressed the overextended and
disorganized mass on both sides, the momentum of the Roman attack dissolved and the troops
were no longer under anyone’s control. Hannibal and Mago rallied most of the routing
Gallic and Spanish troops, turning to rejoin the fighting, while on the opposite side of
the field, Hasdrubal charged into the rear of the enemy infantry. As the compression of the legions began, the
utter defeat of the Roman army was now inevitable. With the maniples hopelessly intermingled,
they could no longer reform their lines. To make matters worse, Libyan troops looked
similar to Roman legionaries, having been equipped with Roman armour, helmets and shields,
that they stripped from the dead at Trebia, Trasimene, and Geronium. The legionaries felt they were no longer protected
on the flanks, and with the enemy seemingly amongst them, their nervousness soon turned
to panic. Hannibal turned the strength of the Roman infantry,
their deep overwhelming formation, against them. As their ranks contracted under the pressure
of multiple attacks, centurions and tribunes tried in vain to improvise, as movement became
ever harder in the confined space. Paullus and Servilius fought heroically, leading
a stiff resistance, but both were eventually cut down during the fighting. Small groups of legionaries tried forming
rough formations, but most were too exhausted and stood no chance against the fresh Libyans
who were kept in reserve for most of the day. Some of the Roman troops, weary and fatigued,
simply gave up, no longer having the strength to raise their weapons. As the hours passed, the battle became a one-sided
massacre. The fighting went on until dark, but there
was little to no tactical sophistication in this final stage of the battle, as the Carthaginians
systematically slaughtered most of the trapped infantry. In the end, widespread Roman resistance collapsed
and those who had any strength left in them managed to flee towards the Roman camps and
the nearby towns. Hannibal had won an unbelievable victory! By sundown, some 50,000 Roman infantry and
2,700 cavalry lay dead or dying on the field at Cannae. The gory sight gave pause even to the most
hardened of observers, as nearly 3,000 tonnes of human flesh was left to rot in the August
sun – the true fruits of Hannibal’s tactical masterpiece. But, achieving this slaughter cost Hannibal
dearly. 5,700 of his men fell, a high figure for a
victorious army in ancient times, which is testament to the harsh fighting on the day,
although it is worth noting that the Carthaginians were significantly outnumbered until the very
end of the battle, which also played a role in the relatively high casualties for Hannibal’s
army. Nevertheless, the Roman leadership was decimated. Consul Paullus, proconsul Servilius, and Marcus
Minucius Rufus were killed in the battle, along with 80 senators, two quaestors, 29
out of 48 military tribunes, some 300 equestrians, with many others captured and enslaved. Never has there been a defeat that struck
so hard at the very heart of Roman society. And… as night fell on August 2nd, 216 BC,
Rome’s very future was left in doubt.
