One of the greatest strategists, a hero in his time who undertook one of the most daring feats in military history, paid the price for his own arrogance and impetuosity with the loss of achieving the thing he desired most – the conquest of Rome. 
A single act of impetuosity led to the destruction of half his army, ruining one of the great invasions of history.
I am referring to Hannibal, Commander of the Carthaginian army at the tender age of 22. In 218 BC Hannibal set off from Cartagena (near present day Tunis) and decided to lead an army of 50 000 troops, 9000 horses and pack animals, and 37 elephants directly across the little known Alps in order to conquer Rome. It was a bold and audacious maneuver and one that was to become ‘one of the most second-guessed troop movements in history’ according to author Stephen Weir. However, in such indiscriminate impetuosity lay the seed of Hannibal’s ultimate failure.
On the decent Hannibal’s army found the going far tougher than they had encountered on the way up. The pathway down was uncertain and the footing treacherous with a lethal mixture of mud and ice to negotiate. During the decent an early autumn snowstorm added to the challenges faced, causing the horses and elephants to become stuck bringing the entire army to complete halt. It was at this point that Hannibal, furious at the delay and the possible cost it might have on his element of surprise, marched to the front and slammed his walking cane into the ground to prove that solid ground lay beneath. That single act of hitting the ground, at a place where a mere whisper is enough to trigger a deadly Alpine avalanche, proved more than enough to trigger an enormous slide. It took four days for Hannibal’s army to dig themselves out and by the time he emerged from the Alps, 15 days after having entered this unchartered territory, Hannibal had less than half his army intact and only a handful of elephants and pack animals. History shows that Hannibal was still able to defeat the Roman army on the plain of Cannae, but he had insufficient forces to attack Rome itself – his ultimate goal.
Hannibal’s trek across the Alps provokes awe and is one of the most famous verifiable incidents of ancient times. However, in his moment of madness Hannibal destroyed his campaign before it had even begun. In fact it is not unreasonable to suggest that Hannibal’s act of anger that triggered the destruction of most his resources, changed the entire shape of European civilization. Victory for the Carthaginians, essentially an African power, could have led to a very different world from the one the Romans did so much to shape. Hannibal’s downfall is a reminder of the lessons to be learnt from the classic tale of the tortoise beating the hare and his journey from Spain to Italy serves several stark reminders to contemporary leaders who find themselves in their own treacherous ‘Alps’:
- In unchartered terrain, slow is sometimes better than fast
- Caution in sometimes better than risk – especially when the footing is uncertain
- The summit doesn’t mean the end of the journey – going downhill can be tougher than going uphill
- Unreasonable ranting can lead to events that ultimately bury you
- Pride always comes before a fall (or avalanche)
- Getting stuck is part of the journey; what you then do about it matters a great deal
Hannibal’s younger brother Hasdrubal, answering a call for reinforcements, followed Hannibal’s footsteps over the Alps where he succeeded in getting his entire army (and animals) over safely. He was also able to persuade some 30 000 additional men from various Gallic tribes to join his cause. However, the Romans this time were ready and waiting for Hasdrubal and proceeded to destroy his army as soon as it entered Italy. The Romans beheaded the unfortunate Hasdrubal and by tossing his head into Hannibal’s camp, provide us with one more salient leadership lesson: getting a head might not always be the best thing!
It really is debatable whether he took that many men with him – considering the numbers he had a few years before, he’d have needed to double the size of his army strength in just the winter months – and he’d have known how useless an army of fresh raised levies would have been.
I’m more of the opinion that the army he exited the Alps with was pretty much the army he left Carthage with – a telling point may be his decision not to engage the Romans who were but a few days march from him. The choice not to engage may reveal the size of his army, and the need to get to Gaul to enlist the Celts.
Hannibal’s Invasion Force: By the Numbers
When Hannibal left New Carthage during the late Spring of 218 BC, according to Polybius his army amounted to 90,000 infantry, 12,000 cavalry (Polybius, 3.35), while Appian adds 37 elephants to the number. Clearly, the size of his infantry and cavalry are exaggerated, and the true size of Hannibal’s invasion force will not be known with certainty, but there are a few considerations – particularly logistical – to take into account when viewing these figures.
First we must discover the reported figures for the size of the Carthaginian army before Hannibal took over – when Hasdrubal the Fair was in charge. According to Diodorus, in retaliation for the betrayal and killing of Hannibal’s father, Hamilcar in 225 BC, Hasdrubal moved against the Oretani with an army made up of 50,000 infantry, 6,000 cavalry and 200 elephants (Gabriel, Hannibal, p.72). Four years later, after his assassination and Hannibal took command, that number had increased to 60,000 infantry and 8,000 cavalry – in a four year time period (225-221 BC) the number had risen 10,000 and 2000 respectively. It was with this army Hannibal conducted two successful campaigns against the Spanish between 221-218 BC, along with the siege of Saguntum before retiring his troops to winter quarters. If we take Polybius’ numbers, we have to believe that Hannibal had just a matter of months to raise 30,000 infantry and 4000 cavalry to make up this number over the course of the winter.
Polybius tells us that Hannibal also left behind a force with his brother, Hasdrubal, made up of 12,650 infantry and 2550 cavalry to guard the Spanish coast. In order to do this Hannibal would have had to make up 42,000 new infantry and 6,550 new cavalry in the winter to be able to raise the force for Hasdrubal and still have 90,000 infantry and 12,000 cavalry declared by Polybius in the few months of winter. Gabriel believes new reinforcements could not have come from Carthage. The reported troop transfers were nothing more than swapping Spanish infantry for more reliable African infantry with no real gain of numerical strength. (Gabriel, Hannibal, pp.101-3).
Engels (Alexander the Great, pp.3-18)has estimated that there was one mule per 50 men for transport, and one camp follower for every three soldiers – which would increase the total number of people to 136,000 for Hannibal’s march. Per day per man would need 3 pounds of rations. This would make it necessary that a total of 408,000 pounds of rations had to be obtained daily to feed the troops. Add to this the 120,000 pounds of grain needed for the horses per day. Around 2700 pack animals would be needed to carry this amount of food for a day, plus another 2000 or so for equipment and heavy baggage. To feed these pack animals, troops and horses for ten days, one would need 55,520 pack animals (Shean, Hannibal’s Mules, p.171 Table 1)
Gabriel has calculated the length of Hannibal’s column would have been more than 100 miles long based on American logistical calculations that an infantry brigade comprising 6310 men and 1021 animals occupied a road space of 4.8 miles, (Gabriel, p.103) – a column of Hannibal’s length could not make the reported 80 stades (9 miles) a day that Polybius implies was Hannibal’s rate of movement (Polyb. 3.50)
What then, were his numbers? We have to take into account of attrition during Hannibal’s campaigns in Spain from 221-218 BC – but we have very little to estimate casualty figures. Gabriel assumes that we should look at a 10 percent casualty figure for these campaigns (including Saguntum) which would make the figure of Hannibal’s army before he dispersed for winter around 54,000 infantry and 7000 horse. From this we can deduct the force given to Hasdrubal Barca leaving Hannibal’s invasion force a much more manageable 40,000 infantry and 5000 cavalry.
With this force he supposedly fought four tribes north of the Ebro river; the Ilurgetes, the Bargusii, the Aerenosii and the Andosini, leaving Hanno in command of a force made up of 10,000 infantry and 1000 cavalry (along with his heavy baggage) to defend the region. The only tribe of significance were the Ilurgetes, and even coming up against token resistance Hannibal could not have marched an army 100,000 strong in the time Polybius and Livy imply Hannibal took to cover the distance from the Ebro to Emporion.
What then, was the purpose of Hanno’s force? We have to question its historicity by the actions that followed. Hanno was reportedly more than 150 miles south of the only strategic location in the region; that of the Greek coastal city of Emporion, supposedly fighting rebels. Hanno did not attempt to lay siege to the city that would see Gnaeus Scipio disembark at the head of a Roman army a few months later. Hanno made no attempt to protect the Spanish coast. The answer was his force was unable to conduct offensive operations. It is more likely that Hannibal did not in fact leave such a force behind as it would have achieved nothing of significance in the region, being unable to defend the Spanish coast or capture the strategic Greek city of Emporion (Gabriel, p.105-6). Hannibal only had around 40,000 troops, and could hardly have afforded to leave such a pointless force behind. More likely, his plan was to defend and hold the line at the Ebro River, where Hasdrubal’s main force was located, and where there was friendly tribes and well supplied magazines and solid interior lines linking up with New Carthage. Hannibal was well aware that he could not defend the area north of the Ebro sufficiently against Rome’s superior numbers of warships and transports.
Naturally, any attempt to discover the true figure is impossible, and the above analysis is flawed due to the nature of reported ancient figures and ancient sources in general – but Gabriel’s approach is certainly an interesting and fresh perspective of the numbers – despite the unreliability of the source figure of Diodorus’ in regards to the size of Hasdrubal the Fair’s army in 225 BC!
It’s also flawed due to ultimately guess-work on ancient logistics, but it does give a good idea how supplying armies (especially stupidly large ones) would have been far from simple.
Essentially, Hannibal needed to get to Italy quickly. Dragging 90,000 soldiers (half of which would have been poorly trained and of little use on a long march, let alone battle), and tens of thousands of pack animals would have slowed him down a lot, and would have also presented a possible large danger to those whose country he was traveling through… Another point to consider, if Hannibal’s army was so large, why did the Romans think they could deal with it with the reduced legions they sent to Spain under the consul P. Scipio?
Another explanation of the numbers which could explain such a high figure could be that that the numbers simply revealed Carthage’s complete military strength they had in Spain by mid-year – this is a very plausible analysis.
That’s not to mention the fact that the Roman sources pretty much always reveal Carthaginian armies as massive beasts, and it was one way to explain why it wasn’t so large when it exited the Alps. It was a great strategic decision, one that prevent the invasion of Africa which the Romans were preparing to do from the beginning of the war.
Stephen Weir’s analysis doesn’t consider the context of the war at all, or the nature of ancient warfare. It is pretty terrible to be honest.
Bibliography
Polybius, The Rise of the Roman Empire, Penguin Classics, 1979
Gabriel, Hannibal, Potomac Books, 2011
Shean, Hannibal’s Mules, 1996