Battle of Cannae – August 2, 216 BC
Battles are rarely fair. By design a successful General will understand his enemy and use their tactics against them. Hannibal was one of the most successful Generals in history not because he was hyper aggressive, not because he had a technical or training edge or a super weapon. Hannibal had none of these things, instead Hannibal who was greatly outnumbered, used Roman tactics against his enemy and destroyed them completely, ruthlessly, and utterly.
Precursor
Rome and Carthage were long time enemies, fighting multiple times in the Punic wars. In the second Second Punic War, Carthage was eyeing Spain and Sicily to expand its city empire. In order to do this, Carthage needed to take the initiative against the Romans and invade their territory in what could be described as a war of intimidation.
The Second Punic War saw an invasion of Italy by Hannibal in an amazing feat in terms of road marches as Hannibal lead his army through the Pyrenees and the Alps. He quickly crushed the Romans at Trebia and Lake Trasimemne, before encamping near the village of Cannae a very short distance from the capital.
The Roman’s responded by trying to avoid major battles and to attempt to starve out Hannibal by cutting his supply lines. However, the Roman’s were always known for aggressive and attack based battles so this was unpopular in Rome. The Roman’s were also were frightened of Hannibal plundering Italy unopposed as it might lead some of Rome’s close allies to side with Hannibal or get crushed.
This led to Fabius the Dictator responsible for this strategy being basically fired. Varro and Paullus were selected to lead a massive army as co-leaders.
Leaders
Gaius Terentius Varro
Was a politician and Roman General during the Second Punic War, he was in command of the Roman army on the day of Cannae. Considered the more cautious of the two commanders.
Lucius Aemilius Paullus
Was named a two-time Roman Council first in the Illyrian war and then again in the Second Punic War in which he shared command of the Roman Army with Gaius Terentius Varro. Paullus was the more aggressive to the two commanders he was not the overall commander during Cannae
Hannibal
Was the son of Hamilcar Barca, a Carthaginian leader who commanded during the loss to Rome in the First Punic War. Hamilcar encouraged his son’s hatred of Rome. Hannibal was encouraged by his father to hate the Roman Empire and made to swear that he would never be a friend to Rome. Hannibal went on to fight in many battles and eventually rose to command Carthage’s massive invasion army.
The Armies
Romans
Rome at that time usually employed 4 legions at a time. A Legion was a heavy infantry unit supported by calvary. In this case the average Legion was usually about 5000 men, this was comprised of 4200 infantry and about 300 or more cavalry units.
The infantry was armed with a Javelin or throwing spear, the Gladius or short sword designed for stabbing more then slashing, and a heavy Scutum, or a large shield designed to push back the enemy and allow the average soldier to stab from protection. The Roman’s also received protection from their personal armor and helmet.
The Roman Cavalry was armed with a lance and usually carried a Spatha which was a longer sword designed for slashing as well as stabbing.
For the march on Hannibal, Rome had assembled 8 Legions comprised of about 80,000 Infantry and 6,400 cavalry.
Carthage
Hannibal’s army was made up of different allies drawn from France, modern day Germany and africa. The Carthaginian army was estimated to be made up of 50,000 men of mixed units, including infantry from Libya, the excellent Gaul infantry, and various different tribesmen. He had 40,000 infantry men. Roughly 10,000 cavalry that were lighter and faster than the Roman heavy cavalry, and 6000 javelin men who were key to this battle.
Rome badly outnumbered the Carthaginians 80,000 to about 50,000. The Roman’s had an edge in terms of personal kit; however Hannibal was the superior tactician and knew the Romans and their tactics.
Initial deployment
The Roman’s placed their infantry in the center of their scrimmage line with their Cavalry on the wings to protect the Roman flanks and provide speed and mobility. Varro who was in command that day, decided that he wanted to attack the center of Hannibal’s army and because of that he massed his infantry units based on depth more then width and compressed his infantry into a wedge. Its interesting to note that Roman infantry formations in a legion were broken into three rows. The first row was comprised of the raw recruits, the second row comprised of battle-hardened troops and the final row was comprised of experienced veterans. The logical thought being that the Veterans might have been slower, but their experience would allow them to be a powerful and efficient reserve. The idea behind Varro’s decision, was to sunder the middle of Hannibal’s line and pour reenforcments into the rear to savage Hannibal’s reserves and logistics.
Hannibal on the other hand deployed his forces based on the strength of units in a crescent shaped formation. The Gaul’s his best infantry were in the center formation. To bait the trap he put himself front and center in front of the Romans. Meanwhile, he placed his battle-hardened Punic Infantry at the edges of his line. Hannibal then placed his light cavalry on the flanks, and kept his javelin men in reserve.
The Battle Joined
Keep in mind that Hannibal had created the perfect trap and in the span of 4 hours would use Varro’s caution and reliance on text book tactics against him. As the Roman’s advanced they compressed to attack the middle of Hannibal’s battle line, while Hannibal extended the center of his line. Thus, when the Roman’s attacked at the center, we need to think of it like a huge pressure plate attached to the hinged flanks. The Roman’s saw some early success pushing back the Gaul Infantry Units, but the trap was sprung as the outer flanks began to look like a crescent facing the Romans.
Varro’s mistake of compressing his formations was about to blow up in his face as Hannibal’s cavalry swept in on the flanks engulfing the Roman’s formation including the Roman cavalry. The Hispanic and Celtic Horsemen of Hannibal’s army then dismounted due to a lack of maneuver room and engaged in a brutal battle as they pushed the Roman’s towards the center. On the other flank Hannibal’s cavalry occupied the Roman Cavalry designed to protect Varro’s flank and pushed them towards the center.
The Roman’s were trapped in the center facing infantry on all sides. To illustrated how desperate the situation was for the Romans, think of taking 80,000 Roman’s and putting them in a room designed to hold half that number. The center of the Roman army was crushed in and paralyzed and could not effectively fight.
The Roman’s were trapped, but they still had an avenue of escape, but Hannibal was about to finish his encirclement. Hannibal ordered the slow retreat of the center of his infantry lines, thus drawing the Roman’s deeper into the sack and then slammed the door shut. His African Infantry including the Javelin men who had been held in reserve moved into the rear of the Roman army thus slamming the circle shut, this was one of the earliest uses of the Pincer movement.
With the Carthaginian cavalry attacking the Romans in the rear and Hannibal’s infantry attacking from the left and the right, the Roman advance to the middle stopped, and Hannibal ordered a counter attack to the middle.
What followed was a massacre of the Roman’s in the middle as all sides of the Carthaginian army advanced. The Roman’s on the outer ranks were mowed down and the Roman’s retreated to the middle and were slaughtered.
Out of 80,000 Romans only 14,000 managed to fight their way out of the trap. Paullius was caught in the middle was wounded and refused to leave. Instead he calmly sat on a rock to await his fate and was slaughtered.
Varro managed to escape and make his way back to Rome, Stunningly he was welcomed back as a hero of the people and thanked for not killing himself, he was then appointed a new army command in the field.
In the end, the Roman’s lost their whole army with a loss of 70,000 infantry killed and 10,000 taken captive with maybe 3,000 surviving. Out of their 6000 cavalry, only a handful made it out alive.
While it was one of the greatest victories in military history, Hannibal paid a steep bill. He lost 8000 of his men and his army was gutted.
Repercussions
When word got back to Rome, it created widespread panic. Their army had been destroyed piecemeal in the field and the loss of moral was massive.
The expectation was that Hannibal would descend on Rome and lay siege to the Capital ending the Roman Empire. In their panic the Roman’s turned to their gods and resorted to human sacrifice. The Romans had seen the loss of their young men in great numbers and it would take years to recover.
But the attack on Rome never came. While Hannibal was urged to march on Rome, he had seen a huge loss to his army, and without the chance of resupply and the difficulty in replacing his losses he didn’t see the ability lay a long siege on Rome. instead Hannibal sent a delegate to Rome to discuss moderate terms with the Roman Senate and was rebuffed. Hannibal then went on a Rampage through the Italian country side for the next 14 years, before being recalled home to defend Carthage.
The Roman’s took the opportunity to reform their army, they banned the word Peace from their language and went back to hit and fade tactics against Hannibal. Tactics wise, the Roman army changed they went to smaller and more mobile formations, The Roman army also changed its command structure and updated the use of cavalry and mobility warfare as well as investing in barrage weapons.
The Roman’s also had to rebuild their depleted ranks and opened their ranks allowing even younger men, criminals and slaves to be conscripted into their ranks. Because of this softening of requirements Rome was quickly able to rebuild its strength.
The Roman empire rebounded and eventually defeated Carthage, first reducing it to a client state of the Roman Empire, then in the Third Punic War pretty much destroying it.
Hannibal was forced into exile after the Roman’s accused him of conspiring with Rome’s enemies to overthrow the Imperial rule of Carthage. He fled the Roman assassins and eventually poisoned himself.
Conclusions
Hannibal has to be considered to be one of the greatest generals of all times, and one of the fathers of mobility-based combat. He was the rare combination of brilliant tactician and charismatic leader. These traits allowed him to not only recruit an army of multinationals but to use them effectively based on the strength and weaknesses of these different units and cultures
Tactically he was brilliant, he understood what Varro intended to do and created a trap based on Roman tactics.
Hannibal’s unwillingness to march on Rome will always be debated because he had the Roman’s on the ground and refused to cut out their heart. He was in fact in a similar situation as the Japanese at the start of WW2 where they realized that they would eventually lose to the Americans and did not have the strength to push their advantage. In his heart Hannibal knew that he could not strike the death blow and was effectively trapped into a course of defeat.
While the Roman’s went through perils in the past, the defeat at Cannae seemed to signal the decline and eventual defeat of the Roman Empire. That did not happen as Rome was given the time to rebuild and reform and eventually destroy Carthage.