How Ancient Horse-Dung Bacteria is Helping Locate Where Hannibal Crossed the Alps

How Ancient Horse-Dung Bacteria is Helping Locate Where Hannibal Crossed the Alps

Chris Allen / The Conversation

Despite thousands of years of hard work by brilliant scholars, the great enigma of where Hannibal crossed the Alps to invade Italy remained unsolved. As a microbiologist, I was part of the team that carried out the research.

Hannibal was the leader of the Carthaginian army during the Second Punic War with Rome (218-201BC). He famously led his 30,000 assorted troops (including 37 elephants and over 15,000 horses) across the Alps to invade Italy – bringing the Roman war machine to its knees. While the great general was ultimately defeated after 16 years of bloody conflict, this campaign is now regarded as one of the finest military endeavours of antiquity. We can say, in retrospect, that these events ultimately shaped the later Roman Empire and therefore the European civilisation as we know it.

For more than 2,000 years historians, statesmen and academics have argued about the route he took. Even Napoleon is known to have shown an interest. But until now, there’s not been any solid archaeological evidence.

Our international team, led by Bill Mahaney of York University in Toronto, have finally provided solid evidence for the most likely transit route: a pass called the Col de Traversette . This narrow pass between a row of peaks is located on the border slightly south-east of Grenoble in France and south-west of Turin in Italy. Our findings are published in Archaeometry.

Col de Traversette. Luca Bergamasco/Wikimedia. ( CC BY 3.0 )

The Traversette – found at about 3000m above sea level – is a torturous path even today. The route was first proposed over a century ago by the biologist and polymath Sir Gavin de Beer , but was not previously widely accepted by the academic community.

Up to this point, many scholars have instead favoured other routes across such as the Col du Clapier , about 2400m high and further north, which is certainly less treacherous today. This popular choice was largely down to the writings of both modern and ancient historians such as Livy , who lived in Padua around 200 years after the historical event but never actually visited the site of the crossing in his lifetime. So it may be that many of Livy’s accounts are more fictional than factual.

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Bed of excrement

Using a combination of microbial genetic analysis, environmental chemistry, pollen analysis and various geophysical techniques, we unveiled a mass animal deposition of faecal materials – probably from horses – at a site near the Col de Traversette. The dung, which can be directly dated to around 200BC through carbon isotope analysis (very close to the date on historical records - 218BC), was found at a mire or pond. This is one of the few in the area that could have been used for watering large numbers of animals. The site was originally discovered during geological expeditions to the area, and already fitted descriptions of the terrain – including rockfalls – that Hannibal had to work his way through.

Over 70% of the microbes in horse dung are from a group known as Clostridia and we found these microbes in very high numbers in the bed of excrement. Much lower levels of Clostridia genes were found elsewhere at the site. We knew it was these bugs because we were able to partially sequence genes specific to these organisms. The bacteria are very stable in soil, surviving for thousands of years.

Aerial photo of expedition site. Peeter Somelar of the University of Tartuu (Estonia), Author provided.

So why did Hannibal choose the more difficult Traversette crossing? At this point we can only speculate, but he may not have had a choice at all. Hannibal wasn’t just worried about the actions of the Roman army at this time. In these relatively ancient days there were Gaulish tribes in the region, a major military force, and Hannibal may have been forced to take this more difficult and unexpected route to avoid a devastating ambush.

The finding is exciting, however we cannot yet be absolutely certain that these bacteria do actually come from horses or humans. The gene analysis needs to be expanded with more genetic sequencing of other genes, if this conclusion is to be certain. I am currently leading an extensive microbiology programme to try and assemble either complete or partial Clostridia genomes from the samples taken at the Traversette mire.

We may also be able to find parasite eggs – associated with gut tapeworms – still preserved in the site like tiny genetic time capsules. With this information, we hope to shed considerable light on the presence of horses, men – and even Hannibal’s famous elephants – at the Traversette mire over 2,000 years ago. This is because with more genetic information we can be more precise about the source and perhaps even the geographical origin of some of these ancient beasts by comparison with other microbiology research studies.

Featured image: Hannibal crossing the Alps on elephants. Source:

The article, originally titled ‘ How ancient horse-dung bacteria is helping our team locate where Hannibal crossed the Alps ’ by Chris Allen was originally published on The Conversation and has been republished under a Creative Commons license.

Ancient horse dung helps researchers find Hannibal’s path across the Alps and into Rome

More than 2,000 years ago, Carthage’s greatest general, the feared Hannibal, crossed the Alps on a treacherous journey to the Italian Peninsula. The brilliant maneuver caught Rome with its pants down as no one dared think someone would be foolish enough to cross an entire army through such terrain. The exact path Hannibal took in this epic voyage across the Alps has been a matter of debate among scholars, but now scientists think they’ve finally found it by following some unlikely bread crumbs: ancient horse dung still teeming with preserved bacteria left by Hannibal’s cavalry.

The findings were made in a site near Col de Traversette, which is 3,000 meters above sea level and very difficult to cross even with backpack, let alone a 30,000 strong army with 37 elephants and 15,000 horses, as historians account. This path was first proposed as Hannibal’s preferred route almost a century ago by Sir Gavin de Beer, but other scholars dismissed it since there were other paths through the Alps that were much easier to cross like the Col du Clapier, which is further up north, but only 2,400 meters high and much less treacherous.

Writing for The Conversation, archaeologist Chris Allen of Queens University said they were drawn to a pond at Col de Traversette after a geological expedition reported the site strangely resembled descriptions of the terrain Hannibal went through across the Alps. Digs at the site “unveiled a mass animal deposition of faecal materials” most likely from horses since 70% of the microbes were identified as belonging to the group Clostridia, partial genetic sequencing revealed. The microbes can survive sequestrated in the soil for thousands of years.

“Much lower levels of Clostridia genes were found elsewhere at the site,” wrote Allen.

Aerial photo of expedition site. Peeter Somelar of the University of Tartuu (Estonia).

There was also evidence of horses trudging through the muck, despite few mammals venture through this passing. The dung “can be directly dated to around 200BC through carbon isotope analysis (very close to the date on historical records – 218BC),” Allen wrote.

“We may also be able to find parasite eggs – associated with gut tapeworms – still preserved in the site like tiny genetic time capsules. With this information, we hope to to shed considerable light on the presence of horses, men – and even Hannibal’s famous elephants – at the Traversette mire over 2,000 years ago.”

Allen reckons Hannibal chose to take this more difficult route in favor of more accessible options to avoid ambushes from neighboring Gaulish clans. The jury is still out though, but this is really the first tangible evidence we have of Hannibal’s crossing through the Alps apart from the historical records, the researchers reported in the journal Archaeometry.

Though he ravaged the Italian countryside for several years and won several important battles, he was eventually defeated by the tactics of Quintus Fabius Maximus, who realized he could defeat Hannibal by attacking the one thing he could not replace–his men. He began forcing Hannibal to fight small, costly engagements instead of direct conflicts. These “Fabian” tactics are still used today we know them as “wars of attrition.” Realizing that Hannibal’s army was outrunning its supply lines quickly, Rome took countermeasures against Hannibal’s home base in Africa by sea command and stopped the flow of supplies. Hannibal quickly turned back and rushed to home defense, but suffered defeat in the Battle of Zama (202 BC).

Ancient dung helps scientists unlock Hannibal mystery

Scientists may have unlocked one of the great puzzles of the ancient world, analyzing microbes from horse manure to discover where Hannibal and his army crossed the Alps.

The Carthaginian general famously led an army of 30,000 men, 37 elephants and more than 15,000 horses and mules to invade Italy. The audacious trek across the Alps occurred during the second Punic War, which lasted from 218 B.C. to 201 B.C.

However, Hannibal’s exact route across the Alps has been hotly debated by historians. Now, an international team of scientists have unearthed fascinating evidence from the remote Col de Traversette pass on the border between France and Italy.

Harnessing radiocarbon dating, microbial metagenome analysis, environmental chemistry and pollen analysis, the experts have shown that a “mass animal deposition” event occurred near the Col de Traversette in 218 B.C.

The expedition to the Col de Traversette site (Queen's University, Belfast)

“You’re looking at a lot of horses -- as anybody that knows anything about horses will tell you, when horses drink, they have to defecate,” Chris Allen, senior lecturer in environmental microbiology at Queen’s University, Belfast, told, explaining that scientists studied 3 feet of sediment beneath a large mire, or pond, for evidence of the horses’ manure.

More than 70 percent of the microbes in horse manure are from a group known as Clostridia that can survive in soil for thousands of years. Allen told that scientists found a remarkable increase in the number and relative abundance of the bacteria in the sediment, suggesting that Hannibal’s army crossed the Alps at that specific point.

“Normally, we see these bacteria at quite low levels within soil, but, in this particular case, we found very high relative numbers,” he said. Scientists also noticed an increase in the number of bile salts that come from the gut, as well as a sharp change in the sediment’s pollen record. “The pollen analysis showed us that there was definitely a significant change in the deposition characteristics at the point Hannibal crossed the Alps,” explained Allen.

The microbiologist acknowledges that researchers were fortunate to find the mire, which dated back 8,000 years. Other mires in the area were less than 2,000 years old, so were unable to yield any information on Hannibal’s army.

At this stage, scientists are not sure how much Hannibal’s elephants have contributed to the evidence. “Basically we are looking at there likely being a lot more horse manure than elephant,” Allen explained. “But we don’t know yet.”

The project was a collaboration between Queen’s University, Toronto’s York University, Ireland’s Dublin City University, Estonia’s Tartu University and researchers in Canada, Portugal, France and the U.S. Professor Bill Mahaney of York University led the expedition to the Col de Traversette, with University of Toronto Associate Professor Sarah Finkelstein providing pollen analysis. Arizona-based radio carbon dating expert Alan West also participated.

The scientists’ findings, which are published in the journal Archaeometry, may even boost our understanding of modern bacteria, according to Allen. “There’s not a lot that we know about Clostridia over the last 2,000 years,” he said. “We hope that some of the information that we get from this may tell us about how these organisms have changed in the last 2,000 years and help us with medical discoveries.”

Bed of excrement

Using a combination of microbial genetic analysis, environmental chemistry, pollen analysis and various geophysical techniques, we unveiled a mass animal deposition of faecal materials – probably from horses – at a site near the Col de Traversette. The dung, which can be directly dated to around 200BC through carbon isotope analysis (very close to the date on historical records – 218BC), was found at a mire or pond. This is one of the few in the area that could have been used for watering large numbers of animals. The site was originally discovered during geological expeditions to the area, and already fitted descriptions of the terrain – including rockfalls – that Hannibal had to work his way through.

Over 70% of the microbes in horse dung are from a group known as Clostridia and we found these microbes in very high numbers in the bed of excrement. Much lower levels of Clostridia genes were found elsewhere at the site. We knew it was these bugs because we were able to partially sequence genes specific to these organisms. The bacteria are very stable in soil, surviving for thousands of years.

Aerial photo of expedition site. Peeter Somelar of the University of Tartuu (Estonia), Author provided

So why did Hannibal choose the more difficult Traversette crossing? At this point we can only speculate, but he may not have had a choice at all. Hannibal wasn’t just worried about the actions of the Roman army at this time. In these relatively ancient days there were Gaulish tribes in the region, a major military force, and Hannibal may have been forced to take this more difficult and unexpected route to avoid a devastating ambush.

The finding is exciting, however we cannot yet be absolutely certain that these bacteria do actually come from horses or humans. The gene analysis needs to be expanded with more genetic sequencing of other genes, if this conclusion is to be certain. I am currently leading an extensive microbiology programme to try to assemble either complete or partial Clostridia genomes from the samples taken at the Traversette mire.

We may also be able to find parasite eggs – associated with gut tapeworms – still preserved in the site like tiny genetic time capsules. With this information, we hope to shed considerable light on the presence of horses and men – and even Hannibal’s famous elephants – at the Traversette mire over 2,000 years ago. This is because with more genetic information we can be more precise about the source and perhaps even the geographical origin of some of these ancient beasts by comparison with other microbiology research studies.

This article was originally published on The Conversation . Read the original article .

The truth about Hannibal’s route across the Alps

H aving battled their deadly rivals the Romans in Spain, in 218BC the Carthaginian army made a move that no one expected. Their commander Hannibal marched his troops, including cavalry and African war elephants, across a high pass in the Alps to strike at Rome itself from the north of the Italian peninsula. It was one of the greatest military feats in history.

The Romans had presumed that the Alps created a secure natural barrier against invasion of their homeland. They hadn’t reckoned with Hannibal’s boldness. In December he smashed apart the Roman forces in the north, assisted by his awesome elephants, the tanks of classical warfare. Many of the animals died of cold or disease the following winter, but Hannibal fought his way down through Italy. For 15 years he ravaged the land, killing or wounding over a million citizens but without taking Rome. But when he faced the Roman general Scipio Africanus at Zama in north Africa in 202BC, his strategic genius met its match. So ended the second Punic war, with Rome the victor.

Hannibal’s alpine crossing has been celebrated in myth, art and film. JMW Turner made high drama of it in 1812, a louring snowstorm sending the Carthaginians into wild disarray. The 1959 sword-and-sandals epic movie, with Victor Mature in the eponymous title role, made Hannibal’s “crazed elephant army” look more like the polite zoo creatures they obviously were.

The battles didn’t end with Scipio’s victory, though. Much ink, if not blood, has been spilled in furious arguments between historians over the precise route that Hannibal took across the Alps. The answer makes not a blind bit of difference to the historical outcome, but there’s clearly something about that image of elephants on snowy peaks that makes experts care deeply about where exactly they went.

An international team of scientists now thinks the puzzle is largely solved. Its leader, geomorphologist Bill Mahaney of York University in Toronto, began pondering the question almost two decades ago by looking at geographical and environmental references in the classical texts. He and his colleagues have just revealed surprising new evidence supporting their claim to have uncovered Hannibal’s path.

An illustration of Hannibal crossing the Alps with elephants and horses. Photograph: Getty Images/Dorling Kindersley

The three Punic wars were a struggle for dominance of the Mediterranean region by the two great trading and military powers of the third and second centuries BC: Carthage and Rome. Carthage, a former Phoenician city-state in present-day Tunis, had an empire extending over most of the north African coast as well as the southern tip of Iberia. Rome was then still a republic, and the two states were locked in a power struggle apt to flare into open war, until the Romans annihilated Carthage in 146BC.

Hannibal, son of general Hamilcar who led troops in the first Punic war, gave Carthage its most glorious hour. He is ranked alongside Alexander the Great, Julius Caesar and his nemesis Scipio as one of the greatest military strategists of the ancient world, and his alpine crossing plays a big part in that reputation. Most of what we know about it comes from the accounts given by the Roman writers Polybius (c200-118BC) and Livy (59BC-AD17). They make it sound truly harrowing.

As the Carthaginian army ascended from the Rhône valley in Gaul, they were harassed and attacked by mountain tribes who, knowing the territory, set ambushes, dropped boulders and generally wrought havoc. During the descent the Carthaginians were mostly unmolested, but now the mountains themselves threatened mortal danger. The Alps are steeper on the Italian side, and the path is narrow, hemmed in by precipices.

“Because of the snow and of the dangers of his route [Hannibal] lost nearly as many men as he had done on the ascent,” wrote Polybius. “Since neither the men nor the animals could be sure of their footing on account of the snow, any who stepped wide of the path or stumbled, overbalanced and fell down the precipices.”

At length they reached a spot where the path suddenly seemed impassable, as Livy describes it: “A narrow cliff falling away so sheer that even a light-armed soldier could hardly have got down it by feeling his way and clinging to such bushes and stumps as presented themselves.”

“The track was too narrow for the elephants or even the pack animals to pass,” writes Polybius. “At this point the soldiers once more lost their nerve and came close to despair.”

Hannibal tried a detour on the terrifying slopes to the side of the path, but the snow and mud were too slippery. So instead he set his troops to construct a road from the rubble, and after backbreaking labour he got the men, horses and mules down the slope and below the snowline. The elephants were another matter – it took three days to make a road wide enough. Finally, says Polybius, Hannibal “succeeded in getting his elephants across, but the animals were in a miserable condition from hunger”.

Where exactly Hannibal crossed the Alps was a point of contention even in the days of Polybius and Livy. Nineteenth-century historians argued about it, and even Napoleon weighed in. The controversy was still raging a hundred years later. Some authorities proposed a northerly path, past present-day Grenoble and through two passes over 2,000 metres high. Others argued for a southerly course across the Col de la Traversette – the highest road, reaching 3,000m above sea level. Or might the route have been some combination of the two, starting in the north, then weaving south and north again?

Victor Mature and Rita Gam in the 1959 film Hannibal. Photograph: Alamy

The southern route was advocated in the 1950s-60s by Sir Gavin de Beer, director of the British Museum (natural history), who published no fewer than five books on the subject. He combed the classical texts and tried to tie them in to geographical evidence – for example, identifying Hannibal’s river crossings from the timings of floods. “All of us more or less follow de Beer’s footprint,” says Mahaney.

For Mahaney, it began as a hobby and become a labour of love. “I’ve read classical history since my ordeal getting through four years of Latin in high school,” he says. “I can still see my old Latin teacher pointing his long stick at me.”

He went looking for clues in the landscapes. Both Polybius and Livy mention that the impasse faced by Hannibal was created by fallen rocks. Polybius, who got his information firsthand by interviewing some of the survivors from Hannibal’s army, describes the rockfall in detail, saying that it consisted of two landslides: a recent one on top of older debris. In 2004 Mahaney found from field trips and aerial and satellite photography that, of the various passes along the proposed routes, only the Col de Traversette had enough large rockfalls above the snowline to account for such an obstruction.

There’s an old, steep track of rubble leading out of this pass – which might conceivably be based on the very one made by Hannibal’s engineers. What’s more, in 2010 Mahaney and co-workers found a two-layer rockfall in the pass that seemed a good match for that which Polybius mentioned. “No such deposit exists on the lee side of any of the other cols,” he says.

He suspects Hannibal did not intend to come this way, but was forced to avoid the lower cols to the north because of the hordes of Gauls massing there. “They were every bit Hannibal’s equal, and no doubt hungry to loot his baggage train,” Mahaney says.

The rockfall evidence was pretty suggestive. But could Mahaney and his team of geologists and biologists find anything more definitive? Since 2011 they’ve been looking in a peaty bog 2,580m up in the mountains, just below of the Col de la Traversette. It’s one of the few places where Hannibal’s army could have rested after crossing the col, being the only place in the vicinity with rich soil to support the vegetation needed for grazing horses and mules.

The researchers rolled up their sleeves and dug into the mire. What they found was mud. And more mud. Not very informative, you might think. But mud can encode secrets. Taking an army of tens of thousands, with horses and elephants, over the Alps would have left one heck of a mess. More than two millennia later, Mahaney might have found it.

The peaty material is mostly matted with decomposed plant fibres. But at a depth of about 40cm this carbon-based material becomes much more disturbed and compacted, being mixed up with finer-grained soil. This structure suggests that the bog became churned up when the layer was formed. That’s not seen in any other soils from alpine bogs, and isn’t easily explained by any natural phenomenon such as grazing sheep or the action of frost. But it’s just what you’d expect to see if an army with horses and elephants passed by – rather like the aftermath of a bad year at the Glastonbury festival. This soil can be radiocarbon-dated – and the age comes out almost spookily close to the date of 218BC attested by historical records as the time of Hannibal’s crossing.

Publius Cornelius Scipio Africanus, the Roman general who defeated Hannibal at the battle of Zama in 202 BC. Photograph: Alamy

The researchers then took samples of this disturbed mud back to the lab, where they used chemical techniques to identify some of its organic molecules. These included substances found in horse dung and the faeces of ruminants. There’s some of this stuff throughout the mire mud, but significantly more in the churned-up layer.

What’s more, this section also contained high levels of DNA found in a type of bacteria called clostridia, which are very common in the gut of horses (and humans). In other words, the layer of disturbed mud is full of crap (perhaps not so different from Glastonbury either). Aside from a passing army, it’s not easy to see where it might have come from – not many mammals live up here, except for a few sheep and some hardy marmots.

That’s not all. Microbiologists collaborating with the team think they might have found a distinctive horse tapeworm egg in the samples. “There is even the possibility of finding an elephant tapeworm egg,” says Mahaney’s long-term collaborator, microbiologist Chris Allen of Queen’s University Belfast. “This would really be the pot of gold at the end of the rainbow.” It’s just a shame, he adds, that “the pot of gold is actually a layer of horse manure”. Evidence of elephants at the site would surely be a smoking gun, since you don’t find many of them wandering wild in the Alps.

Meanwhile, Mahaney hopes, if he can find the funding, to mount a radar survey of the entire mire and other mires nearby to search for items dropped by the passing army. “My sniffer tells me some will turn up,” he says – “coins, belt buckles, sabres, you name it.”

Unless they do, other experts may reserve judgment. Patrick Hunt, an archaeologist who leads the Stanford Alpine Archaeology Project, which has been investigating Hannibal’s route since 1994, says that the answer to the puzzle “remains hauntingly elusive”. It’s all too easy, he says, for fellow experts to adduce evidence for their favoured route – his team argues for a more northerly path – but until the same methods and rigour are brought to bear on all the alternatives, none can be ruled out. All the same, he adds, Mahaney is one of the best geo-archaeologists working on the question. “He continues to be a trailblazer in the field,” says Hunt, “and I’d love to collaborate with him, because he’s asking excellent questions.”

If Mahaney can secure firm evidence – such as chemical or microbial fingerprints of elephant faeces – it would be the culmination of a personal quest. “The Hannibal enigma appealed to me for the sheer effort of getting the army across the mountains,” he says. “I have been in the field for long times with 100 people, and I can tell you it can be pandemonium. How Hannibal managed to get thousands of men, horses and mules, and 37 elephants over the Alps is one magnificent feat.”

This article was amended on 15 April 2016. An earlier version implied that horses are ruminants. This is not the case.

After the final Carthaginian naval defeat at the Aegates Islands, [3] the Carthaginians surrendered and accepted defeat in the First Punic War. [4] Hamilcar Barca (Barca meaning lightning), [5] a leading member of the patriotic Barcine party in Carthage and a capable general in the First Punic War, sought to remedy the losses that Carthage had suffered in Sicily to the Romans. [6] [7] In addition to this, the Carthaginians (and Hamilcar personally) [8] were embittered by the loss of Sardinia. After the Carthaginians' loss of the war, the Romans imposed terms upon them that were designed to reduce Carthage to a tribute-paying city to Rome and simultaneously strip it of its fleet. [9] While the terms of the peace treaty were harsh, the Romans did not strip Carthage of her strength Carthage was the most prosperous maritime trading port of its day, and the tribute that was imposed upon them by the Romans was easily paid off on a yearly basis while Carthage was simultaneously engaged by Carthaginian mercenaries who were in revolt. [9]

The Carthaginian Barcine party was interested in conquering Iberia, a land whose variety of natural resources would fill its coffers with sorely needed revenue [10] and replace the riches of Sicily that, following the end of the First Punic War, were now flowing into Roman coffers. In addition, it was the ambition of the Barcas, one of the leading noble families of the patriotic party, to some day employ the Iberian peninsula as a base of operations for waging a war of revenge against the Roman military alliance. Those two things went hand in hand, and in spite of conservative opposition to his expedition, Hamilcar set out in 238 BC [10] [11] [12] to begin his conquest of the Iberian peninsula with these objectives in mind. Marching west from Carthage [13] towards the Pillars of Hercules, [14] where his army crossed the strait and proceeded to subdue the peninsula, in the course of nine years [11] [12] [14] Hamilcar conquered the south-eastern portion of the peninsula. [11] His administration of the freshly conquered provinces led Cato the Elder to remark that "there was no king equal to Hamilcar Barca." [15]

In 228 BC, [11] Hamilcar was killed, witnessed by Hannibal, [16] during a campaign against the Celtic natives of the peninsula. [12] The commanding naval officer, who was both Hamilcar's son in law [12] and a member of the Patriotic party – Hasdrubal "The Handsome" [11] [12] – was awarded the chief command by the officers of the Carthaginian Iberian army. [12] [17] There were a number of Grecian colonies along the eastern coast of the Iberian peninsula, the most notable being the trade emporium of Saguntum. [17] These colonies expressed concern about the consolidation of Carthaginian power on the peninsula, which Hasdrubal's deft military leadership and diplomatic skill [14] procured. For protection, Saguntum turned to Rome Rome sent a garrison to the city and a diplomatic mission to Hasdrubal's camp in Cartagena, [17] informing him that the Iberus river must be the limit of the Carthaginian advance in Spain. [14] [18] The conclusion of the treaty and the embassy were sent to Hasdrubal's camp in 226 BC. [18] [19]

In 221 BC, [16] Hasdrubal was killed by an assassin. [20] [21] [22] It was in that year that the officers of the Carthaginian army in Iberia expressed their high opinion of Hamilcar's 26-year-old [23] son, Hannibal, [22] by electing him to the chief command of the army. [16] [20] Having assumed the command (retroactively confirmed by the Carthaginian Senate [20] ) of the army that his father had wielded through nine years of hard mountain fighting, Hannibal declared that he was going to finish his father's project of conquering the Iberian peninsula, which had been the first objective in his father's plan to bring a war to Rome in Italy and defeat it there.

Hannibal spent the first two years of his command seeking to complete his father's ambition while simultaneously putting down several potential revolts that resulted in part from the death of Hasdrubal, which menaced the Carthaginian possessions already conquered thus far. He attacked the tribe known as the Olcades and captured their chief town of Althaea. [20] A number of the neighbouring tribes were astonished at the vigour and rapacity of this attack, [20] as a result of which they submitted to the Carthaginians. [3] He received tribute from all of these recently subjugated tribes, and marched his army back to Cartagena, where he rewarded his troops with gifts and promised more gifts in the future. [20] During the next two years, Hannibal successfully reduced all of Iberia south of the Ebro to subjection, excepting the city of Saguntum, which, under the aegis of Rome, was outside of his immediate plans. Catalonia and Saguntum were now the only areas of the peninsula not in Hannibal's possession. [24]

Hannibal was informed of Roman politics, and saw that this was the opportune time to attack. He had Gallic spies in every corner of the Roman Republic, even within the inner circles of the Senate itself. [25] The Romans had spent the years since the end of the First Punic War (264-241 BC) [26] tightening their grip on the peninsula by taking important geographical positions in the peninsula in addition to extending Rome's grip on Sicily, Corsica and Sardinia.

In addition to this, the Romans had been at war with the Padane Gauls off and on for more than a century. [27] The Boii had waged war upon the Romans in 238 BC, a war that lasted until 236 BC. [28] In 225 BC, the natives of northern Italy, seeing that Rome was again moving aggressively to colonize their territory, progressed to the attack, [29] but were defeated. [30] The Romans were determined to drive their borders right up to the Alps. [31] In 224 BC, the Boii submitted to Roman hegemony, and the next year the Anari also submitted to the Romans. [31] [32] In 223 BC, [31] the Romans engaged in another battle with the Gauls, this time the Insubres. [33] The Romans at first sustained significant losses against the Insubres while they were attempting to cross a ford near the junction of the Po and the Adda. [31] After encamping in this country for some days without taking any decisive action, the Roman consul on the spot decided to negotiate a settlement with the Insubres. [31] Under the terms of this freshly negotiated truce, the Romans marched out with full honours into the territory of their allies, the Cenomani. [31] However, once they were safe within the territory of the Cenomani, the Romans again marched their army into the territory of the Insubres and were victorious. [31] [34]

In 222 BC, the Celts sent an embassy to the Roman Senate, pleading for peace. Seeing an opportunity for a triumph for themselves, the consuls (Marcus Claudius and Gnaeus Cornelius) vigorously rejected the embassy, and the Gauls prepared for war with the Romans. They hired 30,000 mercenaries from beyond the Alps and awaited the arrival of the Romans. [35] When the campaigning season began, the consular legions were marched into the Insubres territory again. A vigorous combat took place near Mediolanum, which resulted in the leaders of the Gallic revolt turning themselves over to the Romans. [35] With this victory, the Padane Gauls were unhappily subdued, and ripe for revolt.

Hannibal, aware of the situation, sent a number of embassies to the Gallic tribes in the Po valley. In 220 BC, he had begun to communicate intimately with the Padane Gauls (called the "Padane Gauls" because the Po in this era was called the "Padus" by the Romans), and these embassies brought with them offers of money, food and guides to the Carthaginian. [36]

This mission had the specific aim of establishing a safe place for Hannibal to debouch from the Alps into the Po valley. Hannibal did not know a great deal about the Alps, but he knew enough to know that it was going to be a difficult march. He had some scouts give him reports concerning this mountain chain, and he received reports of the difficulties to be encountered there from the Gauls themselves. [36] He did not desire to cross this rugged mountain chain and to descend into the Po valley with exhausted troops only to have to fight a battle.

Hannibal knew enough about the Alps to know in particular that the descent was steeper than the ascent into the Alps. This was one of the reasons he wanted to have allies into whose territory he could march. [a]

The Romans had poorly treated those Gauls whom they had recently conquered, distributing their land to Roman colonists and taking other unscrupulous measures to ensure their own security, against the freshly-conquered tribes. The Insubres, whose tribal territory immediately abutted the Alps, and the Boii, farther down the Po, were particularly pleased with Hannibal's proposed invasion. In addition, much of the Iberian peninsula was populated by related Gallic tribes, [37] and those same Gauls were serving in Hannibal's army. It would be easy indeed to establish intimate relations with these disaffected tribes, especially once he had debouched from the Alps and was amongst them and the Insubres and Boii and other tribes could see and speak with this army for themselves. Polybius had this to say about Hannibal's plans:

Conducted his enterprise with consummate judgement for he had accurately ascertained the excellent nature of the country in which he was to arrive, and the hostile disposition of its inhabitants towards the Romans and he had for guides and conductors through the difficult passes which lay in the way of natives of the country, men who were to partake of the same hopes with himself [38]

These preparations being completed, Hannibal sought to induce the Saguntines to come to arms with him and thereby declare war on Rome through her proxy. He did not desire to break the peace himself, [39] [40] and resorted to a variety of stratagems in order to induce the Saguntines to attack. [39] However, the Saguntines did nothing except send a diplomatic mission to the Romans to complain about the belligerence of the Carthaginians. [39] [41] The Senate, in its turn, sent a committee to Iberia [41] to attempt to settle the issue diplomatically. [39] Hannibal openly scorned the Roman offer in the hopes that it would drive the commission to declare war. However, the commission was not fooled and knew that war was in the air. [39] The commission kept its peace, but brought news to Rome that Hannibal was prepared and was going to strike soon. [39] [41] The Senate took a number of measures in order to free up its hands for the coming conflict with the Carthaginian. An Illyrian revolt was put down with energy, and the Romans sped up the construction of a number of fortresses in Cisalpine Gaul. [39] Demetrius of Pharos had abandoned his previous alliance with Rome and was now attacking Illyrian cities that had been incorporated into the Roman State. [42]

Hannibal could not achieve the ends that he had hoped for, and in the end he sent news to Carthage (where the peace party, his political enemies, were in power) [43] to the effect that the Saguntines were aggressively handling one of their subject tribes, the Torboletes, [39] and encamped in front of Saguntum to besiege it without awaiting any reply from Carthage. Words were exchanged in the Carthaginian Senate to the effect that Hannibal should be handed over to the Romans and his actions disavowed. However, the multitude in Carthage was too much in support of the conflict to order a stop to the war. [39]

The siege took place over the course of eight months, [39] and it is notable that the Romans did not send any aid to the Saguntines in spite of this being a part of the terms of their alliance. The Romans allowed themselves to be tied up in a war against the Illyrians, [39] and did not treat the Carthaginian threat from Iberia with the attention that it deserved.

After the siege, Hannibal sold all the inhabitants as slaves, and distributed the proceeds from those sales to his soldiers. In addition, all the booty from the sacking of the city was taken back to Carthage and distributed to the populace, in order to rally their support to his cause. The rest of the city's treasures were put into his war chest for his planned expedition. [44]

Hannibal had spent the winter after the siege of Saguntum in Cartagena, during which time he dismissed his troops to their own localities. He did this with the hope of cultivating the best possible morale in his army for the upcoming campaign, which he knew was going to be difficult. He left his brother, Hasdrubal in charge of the administration of Carthaginian Iberia, as well as its defence against the Romans. In addition to this, he swapped the native troops of Iberia to Africa, and the native troops of Africa to Iberia. [45] This was done in order to minimize desertion and assure the loyalty of the troops while he was himself busy with the destruction of Rome. He also left his brother a number of ships. [46]

Hannibal foresaw problems if he left Catalonia as a bridgehead for the Romans. They had a number of allies in this country, and he could not allow the Romans a place to land in his base unopposed. As he was relying upon contingents of forces coming to him in Italy via the land route on which he was about to head out, he must take and conquer this country. He had no intention of leaving Iberia to its fate once he was in Italy. Hannibal opted to take the region in a swift campaign, and to that effect he divided his army into three columns, in order to subdue the entirety of the region at the same time.

After receiving route information from his scouts and messages from the Celtic tribes that resided around the Alps, Hannibal set out with 90,000 heavy infantry from various African and Iberian nations, and 12,000 cavalry. From the Ebro to the Pyrenees, the Carthaginians confronted four tribes: the Illergetes, the Bargusii, the Aeronosii, and the Andosini. There were a number of cities here that Hannibal took, which Polybius does not specify. This campaign was conducted with speed in order to take as little time as possible in the reduction of this region. Polybius reports severe losses on Hannibal's part. Having reduced this area, he left his general Hanno in command of this area, specifically over the Bargusii, whom he had reason to distrust due to their affiliation with the Romans. He left his brother in control of this country with 10,000 infantry and 1,000 cavalry. [47]

At this early juncture in the campaign, he opted to send home another 10,000 infantry and 1,000 cavalry. This was done to serve two purposes: he wanted to leave a force of men behind who would retain positive sentiments towards Hannibal himself and he wanted the rest of the Iberians (in his army, as well as out) to believe that the chances of success in the expedition were good, and as a result of which they would be more inclined to join the contingents of reinforcements that he anticipated calling up during the course of his expedition. [47] The remaining force consisted of 50,000 infantry and 9,000 cavalry. [48]

The principal column was the right column, and with it was the treasure chest, the cavalry, the baggage, all the other necessities of war, and Hannibal himself. [49] This was the critical column, and it was no coincidence that Hannibal was with it. As long as Hannibal had no ships to keep himself abreast of the exact movements of the Romans, he wanted to be present in person in case the Romans should make a landing in an attempt to attack his army on its ascent or descent through the Pyrenees. This column crossed the Ebro at the town of Edeba, [50] and proceeded directly along the coast through Tarraco, Barcino, Gerunda, Emporiae and Illiberis. [49] Each of those oppidums was taken and garrisoned in turn.

The second, or central, column crossed the Ebro at the oppidum of Mora and from there information is fairly sparse. [50] It proceeded through a number of valleys in this country, and had orders to subdue any tribes that resisted its advance. It eventually rejoined the principal column when it had completed its task.

The third, or left, column crossed the Ebro where it touches with the Sicoris River and proceeded along the river valley and into the mountain countries. It performed the same task as the second and the first columns did. When planning each of these marches, Hannibal ensured that the Rubrucatus river was athwart each of the columns' paths, so if any of the columns should be placed in a disadvantageous situation the other columns could march up and down the river in support of each other should one be placed in a perilous position by the Barbarians. [49]

The campaign was conducted over the course of two months, and was incredibly costly. Over the course of the two-month campaign, Hannibal lost 13,000 men.

The march to the Rhône after the descent through the Pyrenees was mostly uneventful for the Carthaginians, who had just spent the previous July and August subduing numerous fierce peoples living in the Pyrenees. [51] The countries through which they passed were of different opinions concerning the Carthaginians, the Romans, and the passage of Hannibal's army through their land. Some of these tribes were friendly to Hannibal's cause, while others were opposed to him. [52] That no reports exist of any fighting taking place in this country, in spite of the lack of homogeneity in political leadership amongst the peoples of this area, reflects Hannibal's skill at negotiation. He dealt with each tribe as he marched through their territory, employing his charisma and considerable war chest. [52]

Massalia (modern Marseille), a successful Greek trade emporium, had for some time been under the influence of the Romans, and the Romans had even settled colonists there. Massalia feared the arriving Carthaginian army, and to this effect had sought to influence the native tribes on the left bank of the Rhône (The Eastern Bank) to take up the cause of the Romans. [53] This they were able to do, as the barbarians in this country were to make his crossing of the Rhône problematic.

Publius Scipio, [14] [53] one of the consuls for 218 BC, received orders from the Senate to confront Hannibal in the theatre of the Ebro or the Pyrenees. [53] [54] [55] The Senate delegated to him 60 ships for this purpose. [56] However, he did not move with the speed that the issue required of him. When he arrived in the Po area, there was an uprising amongst the freshly conquered Gauls. [53] [57] More colonies were being established in the Po region, and this caused the Boii and Insubres to arise afresh who were now aware that Hannibal was heading to them. [54] Instead of employing the legions that were on hand for their intended Iberian expedition, the Senate ordered that they should be sent to the Po under the command of a Praetor and new legions should be levied by the consul. [56] [57] The formation of a new army was a fairly easy matter for the Romans. There were so many citizens who were qualified for service in the army that all the government had to do was inform the citizenry that more soldiers were needed and they would be required to serve. Many Romans, being required to serve at some point, spent portions of their youth training to serve in the legions.

Finally, having got these new legions together – in a much more leisurely fashion than the urgency of the situation demanded of him – he set sail from Ostia. In this day there were no compasses, and it was the habit of navigators to sail their ships along the coast and to stop at night for victuals. [58] So, after sailing north along the peninsula's coast (Italian) and then turning west towards the Iberian peninsula, the consul ordered the fleet to stop in Massalia. [56] [59] The time from Ostia to Massalia was 5 days. [56] When he arrived there, to his surprise he learned from the Massaliots that instead of Hannibal still being in Catalonia, as he had anticipated, [59] Hannibal was about 4 days march [60] north of their city on the far side of the Rhône.

Much of Hannibal's marches are shrouded in debate, especially the debate concerning the path he opted to employ over the Alps. However, modern historians agree on where Hannibal encamped his army on the western bank on the Rhône and see the river crossing as clearly conceived and crisply executed. [ citation needed ]

While Rome had been idle and leaving her allies in Catalonia to their fate at the hands of the Carthaginians, the Massaliots, allies of the Romans, were busy rousing the tribes on the left (eastern) bank of the Rhône against the Carthaginians. [53] Upon the arrival of the intelligence of the Carthaginians in the neighbourhood of Massalia, the consul gave up his proposed Iberian expedition and in its stead thought to do the next logical thing, to prevent Hannibal's crossing of the Rhône as best he could. [59] To this effect he sent a column of 300 horse [60] up the left (east) bank of the Rhône with orders to ascertain the exact location of Hannibal's army. [59] Hannibal received similar news to the effect that the Romans had just arrived with one of their consular armies (22,000 foot and 2,000 horse). [61]

Hannibal took advantage of the pre-existing hatred the Celts on the right (west) bank had for the Romans, and persuaded them to aid him in his crossing of this formidable obstacle. [59] [60] He secured from them a number of boats that were capable of making trips at sea, and a numerous collection of canoes of all sorts that must have been employed by the natives of that country. [59] In addition to purchasing these, [59] he was able to acquire their aid in building still other boats. [56] [62] This process of preparing to cross the Rhone took two days. [62]

Awaiting the Carthaginian army on the left bank of the Rhône was a tribe of Gauls called the Cavares. [62] [ dubious – discuss ] This tribe had fortified a camp on the far side of the river, [63] and was awaiting Hannibal's army to cross, [60] so as to attack them as they crossed. [63] There can be no doubt that Hannibal knew of Alexander the Great's crossing of the Hydaspes river in India as from a tactical and strategic standpoint, it is almost exactly the same. Hannibal formulated his plan according to this model (as indeed it is held up as a cookie cutter way to cross rivers, even to cadets at military institutions to this day) ordered one of his lieutenants Hanno, son of Bomilcar to make a northern circuit, [60] [63] to cross the Rhône at a location that he deemed to be suitable for the purpose, and then by forced marches, march south and to take the Barbarian army in flank while he was crossing the river. [63]

The day and the night after all of the boats had been built and gathered, [63] Hanno was ordered up the bank and guided by native Gauls, [60] [63] approximately 40 kilometres (25 miles) [60] [63] upriver at Pont St. Esprit there was an island that divided the Rhône into two small streams. [63] [60] It was here that Hanno decided to cross, and ordered that boats and rafts should be constructed from materials that were at hand. [64] [65] The Carthaginian detachment chopped down trees, lashing the logs together with reliable ropes they had brought with them from the army's stores. [63] [64] By this means, Hanno's corps crossed the river and immediately proceeded south to the barbarian location.

During this time, Hannibal had been completing his preparations to cross the Rhône. [65] At this, the Carthaginian preparations had been particularly obvious and loud – Hannibal had ordered the preparations to be made without concern for secrecy, [65] [63] knowing full well that Hanno's corps was marching down the left (eastern) bank of the Rhône to attack the Cavares. His preparations were designed to draw their attention away from their northern flank and focus their attention on his own preparations. [65] Three days after setting out, Hanno arrived behind a tributary of the Rhone and gave the previously agreed upon signal to let Hannibal know that his force had arrived. [63] [65] Hannibal immediately ordered the boats to cross. [63] [64] The small corps was observing the principal army closely, [63] and on seeing it start its crossing, prepared to descend on the Cavares while the army was crossing.

The crossing itself was carefully designed to be as smooth as possible. Every detail was well thought out. The heavy horsemen were put across furthest upstream, and in the largest boats, so that the boats that Hannibal had less confidence in could be rowed to the left (western) bank in the lee of the larger and more sturdy craft. [64] [65] As for the horses themselves, most of them were swum across the river at the side and stern of each boat. [64] [65] [63] However, some were put on boats fully saddled and ready for immediate use, [64] so that, once they debouched from the river, they could cover the infantry and the rest of the army while it formed up to attack the barbarians. [65]

Seeing that the Carthaginians were finally crossing, the Cavares rose from their entrenchments and prepared their army on the shore near the Carthaginian landing point. [64] [66] The armies started to shout and jeer at each other while the Carthaginian army was in the midst of crossing. [67] These sort of exchanges consisted primarily of encouraging their own men and challenging the other army to battle. Often in antiquity, to intimidate their enemy, armies would be ordered to pound their shields with their weapons and raise loud cries at exactly the same moment to create the greatest amount of noise.

It was at precisely this moment, while the Carthaginian army was in the middle of the stream jeering at the enemy from the boats and the Cavares were challenging them to come on from the left bank, [64] that Hanno's corp revealed itself and charged down on the rear and flanks of the Cavares. [67] [68] A small detachment of Hanno's force was assigned to set the Cavares camp on fire, [67] [68] but the majority of this force reeled in on the stunned Cavares. [68] Some of the Cavares rushed to the defence of their camp, [67] [68] [69] but the majority remained at the location where they had been awaiting the arrival of what they had thought was all of Hannibal's army. [67] [69] They were divided and Hannibal, who was on one of the first boats, landed his men on the left bank of the Rhône amidst the dazed and confused Cavares and with a will led his men in upon them. There was barely even a semblance of resistance [67] surrounded as they were, pandemonium took control of their ranks, and each man looked to his own safety as they retreated pell-mell away from the carefully arrayed Carthaginian phalanx.

While the actual conflict only took a matter of minutes, Hannibal had spent five days preparing this dangerous and risky operation from every angle, ensuring that it was ready at all points and as little as possible was left to chance. [69]

Hannibal needed to reach the Alps quickly in order to beat the onset of winter. He knew that if he waited until springtime on the far side of the mountains, the Romans would have time to raise another army. He had intelligence that the consular army was camped at the mouth of the Rhône. He sent 500 Numidian cavalry down the eastern bank of the river to acquire better information concerning the forces massed to oppose him. This force encountered 300 mounted Romans who had been sent up the river for the same purpose. The Numidians were defeated with 240 of their number killed in this exchange between scouting parties in addition to 140 Roman losses. The Numidians were followed back to the Carthaginian camp, which was almost assembled excepting the elephants, which required more time getting across. Upon seeing Hannibal had not crossed with the whole of his force, the scouts raced back to the coast to alert the consul. Upon receiving this information, the consul dispatched his army up the river in boats, but arrived too late. [66]

In the face of winter and hostile tribes, the consul decided to return to Italy and await the arrival of Hannibal as he descended from the Alps. However, in accordance with the Senate's orders, the consul ordered his brother, Gnaeus Scipio to take a majority of the army to Spain. [66] The consul proposed attacking Hannibal's overextended and vulnerable lines of communications and supply. Despite their established tactical system (formations and troop evolutions, etc.), the Romans were used to fighting by marching their troops to their enemies' army, forming their army up and attacking. They did not know how to force an enemy to battle by cutting off their communications, they were not aware of which flank was the strategic flank of an enemy in a battle. In addition, they were negligent about their order of march, [70] and early Roman history is littered with massacres of consular armies by other nations because of their lack of proper precaution against these evils. [71]

On getting the whole of his army on the left bank of the Rhone, Hannibal introduced his army to Magilus, [66] and some other less notable Gallic chiefs of the Po valley. [66] [72] Hannibal's purpose was to inspire his men with confidence in the planned expedition by showing them Padane Gallic chieftains who offered them their aid. Speaking through an interpreter, [72] Magilus spoke of the support that the recently conquered Padane Gauls had for the Carthaginians and their mission of destroying Rome. Hannibal then addressed the officers himself. The troops' enthusiasm was uplifted by Hannibal's inspiring address. [66]

Upon crossing the river, Hannibal ordered his infantry to start their march the day after the assembly, followed by the supply train. [73] Not knowing that the Romans were eventually going to set out for Italy, when his cavalry had crossed the river he ordered them to curtain his march on his southern flank, towards the sea. [66] His cavalry would have formed a screen which would have been employed to protect him from the Romans were they to advance upon him from that direction. The cavalry would skirmish with the Roman scouts, while giving the rest of the army time to form up. This contingency did not occur. Hannibal was in the rearguard with the elephants. [73] This was the direction that he assumed that the Romans would be most likely to advance from (that is from the west) as he had some idea that they were behind him. The rearguard was well manned to ensure that it could skirmish with the Roman army while the main body of his infantry and cavalry could form up for battle against the Romans if they should attack from that quarter. This contingency, however, also did not occur.

While assuming this order of march, Hannibal marched towards the Insula. [73] He had ordered his infantry to get a head start, and it marched to the Isère in six days, marching 20 kilometres ( 12 + 1 ⁄ 2 miles) per day. The cavalry and rear guard only took four days, a march of 30 km (19 mi) per day. In this period, the body as a whole had marched 120 km (75 mi). [74]

When Hannibal's army made contact with the Insula, he arrived in a Gallic chiefdom that was in the midst of a civil conflict. [75] For whatever reason, Hannibal chose the cause of the elder of the two combatants, Brancus. [74] After putting away the cause of the younger and less popularly supported one, [74] he formed an alliance with Brancus. From this tribe he received supplies that were required for the expedition across the Alps. In addition, he received Brancus' diplomatic protection. Up until the Alps proper, he did not have to fend off any tribes.

Little certainty exists on the route of Hannibal's march through the mountains, and precisely which valleys and passes he used remains contested by historians. The events recorded in ancient accounts and their relationship to the Alpine geography has been a matter of historiographical dispute since the decades following the Second Punic War. Identification of the pass - the highest point of Hannibal's route and the beginning of his descent - that Hannibal took through the Alpine range determines which route his army followed.

Proposals have been made for the following passes: [76] [77] [78] [79] [80]

Theodore Ayrault Dodge, writing in the late nineteenth century, argued that Hannibal used the Little St Bernard Pass, but modern historian John Francis Lazenby concluded that Col de Clapier was the pass used by Hannibal. [81] More recently, W. C. Mahaney has argued Col de la Traversette closest fits the records of ancient authors. [82] Biostratigraphic archaeological data has reinforced the case for Col de la Traversette analysis of peat bogs near watercourses on both sides of the pass's summit showed that the ground was heavily disturbed "by thousands, perhaps tens of thousands, of animals and humans" and that the soil bore traces of unique levels of Clostridia bacteria associated with the digestive tract of horses and mules. [83] Radiocarbon dating secured dates of 2168BP or c.218BC, the year of Hannibal's march. Mahaney et al. have concluded that this and other evidence strongly supports the Col de la Traversette as being the 'Hannibalic Route' as had been argued by Gavin de Beer in 1974. De Beer was one of only three interpreters - the others being John Lazenby and Jakob Seibert de. - to have visited all the Alpine high passes and presented a view on which was most plausible. Both De Beer and Siebert had selected the Col de la Traversette as the one most closely matching the ancient descriptions. [84] Polybius wrote that Hannibal had crossed the highest of the Alpine passes: Col de la Traversette, between the upper Guil valley and the upper Po river is the highest pass. It is moreover the most southerly, as Varro in his De re rustica relates, agreeing that Hannibal's Pass was the highest in Western Alps and the most southerly. Mahaney et al. argue that factors used by De Beer to support Col de la Traversette including "gauging ancient place names against modern, close scrutiny of times of flood in major rivers and distant viewing of the Po plains" taken together with "massive radiocarbon and microbiological and parasitical evidence" from the alluvial sediments either side of the pass furnish "supporting evidence, proof if you will" that Hannibal's invasion went that way. [85]

According to historian Theodore Ayrault Dodge, Hannibal marched in the direction of Mt. Du Chat towards the village of Aquste [86] and from there to Chevelu, [87] to the pass by Mt. Du Chat. There he found that the passes were fortified by the Allobroges. He sent out spies to ascertain if there was any weakness in their disposition. These spies found that the barbarians only maintained their position at the camp during the day, and left their fortified position at night. In order to make the Allobroges believe that he did not deem a night assault prudent, he ordered that as many camp-fires be lit as possible, in order to induce them into believing that he was settling down before their encampment along the mountains. However, once they left their fortifications, he led his best troops up to their fortifications and seized control of the pass. [88]

Hiding his men in the mountain brush on a cliff that arose immediately above and to the right off Hannibal's route of march, about 100 feet or so above the path, Hannibal stationed his slingers and archers there. This overhang was an excellent place from which to attack an enemy while it was marching in column through the pass. [89] The descent from this pass was steep, and the Carthaginians were having a hard time marching down this side of the pass, [89] especially the baggage animals. [88] The Barbarians, seeing this, attacked anyway, in spite of their disadvantageous position. More baggage animals were lost in the confusion of the Barbarian attack, and they rolled off of the precipices to their deaths. [89] This put Hannibal in a difficult situation. However, Hannibal, at the head of the same elite corps that he led to take the overhang, led them against these determined barbarians. Virtually all of these barbarians died in the ensuing combat, as they were fighting with their backs to a steep precipice, trying to throw their arrows and darts uphill at the advancing Carthaginians. [88] After this contest of arms, the baggage was held together in good order and the Carthaginian army followed the road down to the plain that begins roughly at modern Bourget. [90]

Historian Theodore Ayrault Dodge states that this plain was 4–6 miles wide at most places, and was almost entirely stripped of defenders since they were all stationed at the Mt. Du Chat pass. Hannibal marched his army to modern Chambery and took their city easily, stripping it of all its horses, captives, beasts of burden and grain. In addition, there were enough supplies for three days' rations for the army. This must have been welcome considering that no small portion of their supplies had been lost when the pack animals had fallen over the precipice in the course of the previous action. He then ordered this town to be destroyed, in order to demonstrate to the Barbarians of this country what would happen if they opposed him in the same fashion as this tribe had. [90]

He encamped there to give his men time to rest after their exhausting work, and to collect further rations. Hannibal then addressed his army, and we are informed that they were made to appreciate the extent of the effort they were about to undergo and were raised to good spirits in spite of the difficult nature of their undertaking. [91]

The Carthaginians continued their march and at modern Albertville they encountered the Centrones, who brought gifts and cattle for the troops. In addition, they brought hostages in order to convince Hannibal of their commitment to his cause. [91] Hannibal was concerned and suspicious of the Centrones, though he hid this from them [91] and the Centrones guided his army for two days. [92] According to historian Theodore Ayrault Dodge, they marched through the Little St Bernard Pass near the village of Séez, and as they did, the pass narrowed and the Centrones turned against the Carthaginians. Some military critics, notably Napoleon, [93] challenge that this was actually the place where the ambush took place, but the valley through which the Carthaginians were marching was the only one that could sustain a population that was capable of attacking the Carthaginian army and simultaneously sustaining the Carthaginians on their march. [93]

The Centrones waited to attack, first allowing half of the army to move through the pass. [94] This was meant to divide Hannibal's troops and supplies and make it difficult for his army to organize a counter-attack, but Hannibal, having anticipated deceit by the Centrones, had arranged his army with elephants, cavalry and baggage in front, while his hoplites followed in the rear. Centrones forces had positioned themselves on the slopes parallel to Hannibal's army and used this higher ground to roll boulders and rain rocks down at the Carthaginian army, killing many more pack animals. Confusion reigned in the ranks caught in the pass. However, Hannibal's heavily armed rearguard held back from entering the pass, [94] forcing the Barbarians to descend to fight. The rearguard was thus able to hold off the attackers, before Hannibal and the half of his army not separated from him were forced to spend the night near a large white rock, which Polybius writes "afforded them protection" [95] and is described by William Brockedon, who investigated Hannibal's route through the Alps, as being a "vast mass of gypsum. as a military position, its occupation secures the defence of the pass." [96] By morning, the Centrones were no longer in the area.

The army rested here for two days. It was the end of October and snowy weather, the length of the campaign, ferocity of the fighting, and the loss of animals sapped morale in the army's ranks [97] From their outset in Iberia, Hannibal's troops had been marching for over five months and the army had greatly reduced in size. The majority of Hannibal's fighters were unaccustomed to extreme cold of the high Alps, being mostly from Africa and Iberia. [98] According to Polybius, [99] [100] Hannibal assembled his men, declared to them that the end of their campaign was drawing near and pointed to the view of Italy, showing his soldiers the Po Valley and the plains near it, and reminded them they had been assured of Gallic friendship and aid. [97] The Po Valley is not visible from Little St Bernard Pass [101] and if Hannibal took that path it is likely that he pointed in the direction of the Po Valley but it was not in sight. If, however, Hannibal had ascended the Col de la Traversette, the Po Valley would indeed have been visible from the pass's summit, vindicating Polybius's account. [102] After three days of rest, Hannibal ordered the descent from the Alps to begin. [103]

The snow on the southern side of the Alps melts and thaws to a greater or lesser extent during the course of the day, and then refreezes at night. [98] In addition, the Italian side of the Alps is much steeper [98] many men lost their footing down this side of the Alps and died.

At an early point in their descent, the army came upon a section of the path that had been blocked by a landslide. This section of the path was broken for about 300 yards. [104] Hannibal attempted to detour, by marching through a place where there was a great deal of snow – the Alps' altitude at this point retains snowpack year around. They made some headway, at the cost of no small portion of the pack animals that were left, before Hannibal came to appreciate that this route was impossible for an army to traverse. Hannibal marched his men back to the point in their path prior to their detour, near the broken stretch of the path and set up camp. [105]

From here, Hannibal ordered his men to set about fixing the mule path. Working in relays, the army set about this labour-intensive task under the eyes of Hannibal, who was constantly encouraging them. Both the sick and the healthy were put to this. The next day the road was in sufficient condition to permit the cavalry and pack animals to cross the broken stretch of road [105] Hannibal ordered that these should instantly race down below the foliage line (2 miles below the summit of the Alps) [106] and should be allowed access to the pastures there. [105]

However, Hannibal's remaining elephants, which were completely famished, were still unable to proceed along the path. Hannibal's Numidian cavalry carried on working on the road, taking three more days to fix it sufficiently to allow the elephants to cross. [105] Getting the animals across this stretch of road, Hannibal raced ahead of the rearguard to the part of the army that was below the pasture line. [107] It took the army three days to march from this place into "the plains which are near the Po" according to Polybius. Hannibal then focused on, according to Polybius, "[the] best means of reviving the spirits of his troops and restoring the men and horses to their former vigour and condition." [106] Hannibal ordered his men to encamp, at a point which is near modern Ivrea. [108] This effectively marked the end of their crossing of the Alps, but the beginning of their campaign in Italy and their role in some of the decisive battles of the Second Punic War.

In part III of Jonathan Swift's 1726 prose satire, Gulliver's Travels, the eponymous main protagonist, Gulliver, visits "Glubbdubdrib", a fictional island populated by sorcerers. Invited by the governor of the island who is capable of summoning the dead, Gulliver summons Hannibal and learns that he supposedly did not actually utilize fire and vinegar to melt boulders obstructing his path, and that it was probably a conjured up myth. [109]

In The Simpsons episode "Cape Feare", the words 'Terror Lake salutes Hannibal crossing the Alps' can be read on the sides of several elephants as they trample Sideshow Bob.

In the Doctor Who episode "World War Three", The Doctor and Harriet Jones reference Hannibal’s use of vinegar to melt boulders while crossing the Alps.

In the 9th episode of the 3rd season of the motorsport television entertainment series, The Grand Tour, co-host Jeremy Clarkson references Hannibal's crossing of the Alps, comparing the steep terrain-traversing capabilities war elephants of Hannibal's army to that of a Citroën C3 Aircross.

Link: Tracing Hannibal’s invasion using microbes

I know the Hannibal meadow muffin story has done the rounds this week, but I find the approach very interesting: Tracing a historical invasion by looking for trace evidence. One of the principal investigators, Chris Allen, has written about the work himself on The Conversation, and it’s worth pointing people to that synopsis: “How ancient horse-dung bacteria is helping our team locate where Hannibal crossed the Alps”.

Updated: April 7, 2016

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Geologist May Have Found Exact Route Hannibal Used To Cross The Alps-Following a Trail of Dung

In 218 BC, Hannibal marched an army consisting of soldiers, mules, horses and elephants from Spain, over the Alps, and into Italy to attack the Romans at the start of the Second Punic War. His precise route through the Alps has been debated for years.

Bill Mahaney, a geologist and professor emeritus at York University in Toronto, led a team that has found evidence supporting a route proposed by British biologist Sir Gavin de Beer. From their study, it appears that the army marched through the Col de la Traversette on the French-Italian border.

Illustrations from Mommsen’s “Römische Geschichte” page 265, Hannibal.

“If confirmed, the findings presented here have far-reaching implications for solving the Hannibalic route question and, more importantly, for the identification of a site that might be expected to yield significant historical archaeological data and artifacts related to the Punic invasion,” the researchers wrote in the first part of a two-part study published in the journal Archaeometry.

Mahaney has been interested in classical history as a hobby for decades. He knew about the debate over Hannibal’s route and thought he might be able to determine it from descriptions of the geology in historical texts. As an example, the Greek historian Polybius mentions a two-tier rockfall in his account of the trek.

While involved with an unrelated study, Mahaney kept an eye out for clues that matched those descriptions. Over time, he accumulated enough clues to venture a hypothesis as to where the army must have passed.

There is a mire an area where rocky mountain terrain gives way to vegetation, with a stream below the Col de la Traversette that would make a good place to water animals and allow them to feed.

Hannibal´s route of invasion given by the Department of History, United States Military Academy. There is a mistake in the scale. Image Credit.

Mahaney took a team and drilled about 70cm into the soil and retrieved cores of sediment. The cores had 3,000 years of sediment. Within the cores was a layer that was churned up.

“I said to the other guys, ‘You ever seen anything like this?’ They just looked at me.”

Mahaney said he’d pulled “two or three hundred cores from around the world and I’ve never seen anything like this.’“

“So this is either frost or one hell of a group of people coming through with animals churning the hell out of this peat.”

There was no evidence of frost in nearby sites from that time period.

The churned up layer had a lot of organic material, including “some poop – quite a lot of it,” Mahoney said.

Chris Allen, a microbiologist at Queen’s University Belfast in Northern Ireland, analyzed the bacteria in that layer and found that more than 12% were Clostridia. That type of bacteria usually is two or three% of the bacteria found in soil but it is 70% of the bacteria in a horse’s gut. There was also a high amount of bile acids and fats that are found in mammal feces. The evidence pointed toward a large amount of horse and mule dung.

Hannibal and his men crossing the Alps.

“We found scientifically significant evidence of these same bugs in a genetic microbial signature precisely dating to the time of the Punic invasion,” said Allen in a news release.

The team did not manage to find any specific evidence of elephant dung.

“You’d have to get very lucky to find that,” said Mahaney, noting that Hannibal had only 37 elephants (compared to more than 8,000 horses and mules.)

Carbon dating puts the date of the layer at between 26 and 570 BC. This coincides with the period when Hannibal traveled to Italy.

Mahaney said that it was unlikely that the layer could have been left by another large group of animals passing through. There was little reason for such a large group to pass through at such a high altitude. Also, groups smaller than Hannibal’s had presumably passed through at other times, but they had not left a similar mark in the cores.

The team is waiting for the results of analysis of tapeworm eggs found in the layer. They could help pinpoint the geographic origin of the animal that deposited them. Hannibal’s horses are known to have come from Spain.

The study was funded by the QUESTOR Centre, Invest Northern Ireland, the Geological Survey of Ireland, the Irish Research Council, and Quaternary Surveys, as well as through travel and research grants from York University.

Scientists uncover Hannibal’s route through the Alps using horse dung

In one of the boldest moves in ancient history, Carthaginian general Hannibal marched more than 30,000 troops plus some 15,000 horses and 37 elephants across the Alps and invaded Italia, home of the ancient Romans. And yet, despite being legendary, no one knows exactly where Hannibal crossed, but historians have debated the location for over 2,000 years.

Now, researchers from Queen’s University Belfast and beyond seem to have found the answer—and it’s all thanks to poop.

Hannibal was the Commander-in-Chief of the Carthaginian army during the Second Punic War (218-201 BCE)—the second of three bloody contests between Rome and Carthage. Before this particular war began, Hannibal’s father, Hamilcar, took control of parts of what is now Spain, bringing over the Carthaginian army with him. Following his death, Hannibal took over and invaded a city under Rome’s protection, kicking off the Second Punic War.

Rome initially was more or less unworried, thinking that the barrier of the Alps would protect the main part of the empire from the Carthaginians—and they were very wrong. Hannibal did what was seen as impossible, losing many men and animals along the way—but arriving in Italia with enough left to bring the Roman army to its knees. He actually ended up occupying parts of Rome for 15 years before a Roman invasion in North Africa forced him to return to Carthage.

Hannibal was eventually defeated in the Third Punic War at Zama in 202 BCE, but nonetheless he achieved one of the finest military campaigns in antiquity—and his story has fascinated historians ever since.

Where’s the poop, Robin?

Up until now, no physical evidence—like belt buckles or bones—have been found to indicate where Hannibal made his crossing. However, an international team of microbiologists have finally found something…solid. According to the two papers (first and second ) in Archaeometry, the researchers believe Hannibal crossed the Alps via the Col de Traversette pass (

1.9 miles or 3000 meters above sea level), which spans between Grenoble, France, and Turin, Italy.

The Col de Traversette pass was first proposed as an option about fifty years ago, but did not gain much traction in the academic community. But using a variety of techniques like microbial metagenome analysis, environmental chemistry, geomorphic and pedological investigation, and pollen analyses, the researchers have shown that a “mass animal deposition” event dating to about 218 BCE occurred near the pass.

“The deposition lies within a churned-up mass from a 1-meter thick alluvial mire, produced by the constant movement of thousands of animals and humans,” said Dr. Chris Allen, from the Institute for Global Food Security at Queen’s University Belfast, in a statement .

“Over 70 percent of the microbes in horse manure are from a group known as the Clostridia, that are very stable in soil – surviving for thousands of years. We found scientifically significant evidence of these same bugs in a genetic microbial signature precisely dating to the time of the Punic invasion.”

Or in other words, the researchers found evidence of poop—a lot of it. Certainly enough to belong to the thousands of horses Hannibal had with him, and it’s dated to the right time period. And if this discovery should prove to be the discovery of Hannibal’s route, this find is enormous.

“If confirmed, the findings presented here have far-reaching implications for solving the Hannibalic route question and, more importantly, for the identification of a site that might be expected to yield significant archaeological data alongside artifacts related to the Punic invasion,” wrote the authors in the first paper.

“If the site was affected by human–animal traffic, as the evidence indicates, there is every possibility that artifacts such as coins, belt buckles, daggers, equestrian fasteners and so on might have been buried in the mire. If such archaeological evidence can be found and definitively linked to Hannibal, it would answer the question of which route Hannibal and his army took into Italia.”

Horse droppings help identify where Hannibal crossed the Alps

BELFAST, Northern Ireland, April 4 (UPI) — The crossing of the Alps and invasion of the Roman Empire by Hannibal and his army during the Second Punic War is considered by historians to be one of the greatest military campaigns in history, but until now, archaeologists couldn’t say definitively where Hannibal and his troops crossed.

Human evidence of Hannibal’s crossing has been hard to find, but new research has revealed traces of the animals that Hannibal and his army brought with them.

While excavating near a pond along a proposed passing called Col de Traversette, researchers from Queen’s University Belfast discovered a “mass animal deposition” — a layer of ancient excrement. The deposit was confirmed using a combination of microbial genetic analysis, environmental chemistry, pollen analysis and other tests.

Gene fragments sequenced from samples of the deposit suggest the excrement is dominated by microbes from the bacterial group Clostridia. For this reason, researchers believe the excrement was left by horses.

The pond next to the dig site is one of the only water sources on the route large enough to be shared by dozens of animals.

“The bacteria are very stable in soil, surviving for thousands of years,” researchers Chris Allen, a microbiologist at Queen’s University, wrote in The Conversation.

Carbon isotope analysis suggests the horse droppings were left around 200 B.C., close the the historical record of Hannibal’s crossing in 218 B.C.

“The deposition lies within a churned-up mass from a 1-meter thick alluvial mire, produced by the constant movement of thousands of animals and humans,” Allen said in a press release.

Researchers are hopeful that further genetic sequencing from the deposit can shed additional light on the historic crossing.

“We may also be able to find parasite eggs — associated with gut tapeworms — still preserved in the site like tiny genetic time capsules,” Allen said. “With this information, we hope to to shed considerable light on the presence of horses, men — and even Hannibal’s famous elephants — at the Traversette mire.”