What Was Hannibal's Route Over The Alps?

You cannot go far in studying Hannibal without coming across the BIG DEBATE – where did Hannibal cross the Alps?

The first person to complain about different accounts was Polybius, writing only 50 years after the events:

Some of the writers who have described this passage of the Alps … make both false statements and statements which contradict each other…  For they never took the trouble to learn that the Celts who live near the Rhone not on one or on two occasions but quite recently, had crossed the Alps with large armies … nor are they aware that there is a considerable population in the Alps themselves (Book 3, Chapter 47).

Livy, too, alludes to various and erroneous theories:

I am the more astonished at the difference of opinion in regard to his route over the Alps, and that it should be commonly held that he crossed by the Poenine Pass and that from this circumstance that ridge of the Alps derived its name [i.e. on the grounds that the name came from the Punic (Carthaginian) invasion] – or that Coelius should state that he crossed by the ridge of Cremo [i.e. the Little St Bernard Pass]  because both these passes would have brought him down, not amongst the Taurini tribesmen but through the Salassi Montani to the Libuan Gauls. Neither is it probable that these routes to Gaul were open at that time (Book 21, Chapter 38).

Since then, others have offered their suggestions:
Napoleon Bonaparte suggested the Col du Mont Cenis.  
In 1959, the British Alpine Hannibal Expedition, led by engineering student John Hoyte, tried to prove that Hannibal had used the Col de Clapier (slightly to the south) by walking the pass, and taking with them an elephant that they had borrowed from Turin Zoo; the route proved too dangerous and they ended up, instead, going via Mont Cenis Pass (but still thought the Clapier pass was the most likely). 

Another Clapier-Pass advocate, American archaeologist Patrick Hunt (who has directed the Alpine Archaeological Project since 1994), has crossed the Alps 20 times via a number of passes, breaking 30 bones along the way, trying to find a match between the archaeology in the ground, and the accounts in Polybius and Livy.
Meanwhile, Canadian geochemist Bill Mahaney has conducted geo-archaeological investigations (on the soil and rocks) and concluded that the Col de la Traversette in the south is a much better bet.  In 2010, the Wood brothers cycled three different routes for the BBC, before declaring for la Traversette.


A Fruitless Debate, but Fun
Ultimately, it is a fruitless debate, because it cannot ever be solved; indeed, my only original contribution to the debate will be a point which fairly much proves that, even when we think we have solved the PROBLEM, we have not solved THE problem.  

The ONLY truth can be that we will never know.

‘Few historical problems have produced more unprofitable discussion than that of Hannibal's pass over the Alps’, said the English historian Frank Walbank.  But it did not stop him writing extensively on the issue, and it does not stop it being quite FUN to sit in front of your computer, having never actually visited the Alps, and come up with your own theories. (Do it yourself – see if you can find the answer that has eluded the experts!)  Above all, I suspect that – if you are doing the Ancient History GCSE – you will want to have at least an overview of the issue.

The main problem, of course, is the paucity of our source information.  You will read books that tell you what Silenus, and Coelius, said about this and that – but they do not KNOW that, because those accounts are now lost.  Our sources, basically, boil down to Polybius and Livy and – however clever they are – anything anybody suggests beyond that is at best a guess based on references in Polybius and Livy.

Now your guess is NOT as good as Dr Hunt’s guess, of course … but best-guesses they are all when it comes down to it.


The Approach to the Alps

Let’s try and make sure that – even if we guess – our guess is at least a calculated guess.  And it makes sense, if we are to guess which pass Hannibal used, to at least try to gauge some idea about the general direction from which he approached the Alps.

This is harder than it might sound.  Neither Polybius nor Livy tell us the names of many places through which Hannibal passed.  Even where they do, those names have long since fallen into disuse.

So how did Hannibal approach the Alps?

Polybius tells us that he crossed the Rhone at a place about four days' march from the sea, and that he turned east towards the Alps at a place called ‘the Island’, at the confluence of the Rhone and the River Iskaras (in Livy, the ‘Sara’) a further four days' march up the Rhone.

How far did an ancient army march in a day?  Polybius (Book 3, Chapter 50) tells us that, marching (as Livy put it, ‘unhindered’) Hannibal’s army covered 800 stades (145 kilometres) in ten days – about 14 or 15 kilometres a day.  It doesn’t seem very much, but can you remember how – when Hanno took a detachment upstream to outflank the Gauls when Hannibal was crossing the Rhone – they went 200 stades in a night … but ‘were exhausted and needed a day to recover’.  Elephants in particular slowed Hannibal down – when the cricketer Ian Botham tried to take three elephants with him on a charity walk over the Alps in 1988, he had to abandon the idea because they could not keep up.

So traditional wisdom tells us that the 'Iskaras' is the Isère, and that ‘The Island’ is at Valence.  But Valence is 180km from the coast (= 22km a day) which is pushing it a lot.  Other suggestions have been the River Drome (160km = 20km a day, still a bit much) or the Aigues (85km = 10km a day, perhaps not enough – though this was the favoured solution of the British Museum Hannibal enthusiast Gavin de Beer).

The truth is that we will never know, but it is worthwhile noting that – for the more northerly passes (such as the Mont Cenis and the Col de Clapier) to ‘work’ – Hannibal would have needed to drive his army very, very hard up the Rhone before turning east to proceed at a much more leisurely pace eastwards along the River Iskaras.  A more realistic estimate of Hannibal’s progress would favour one of the more southerly passes (Montgenèvre or La Traversette) – and indeed Livy (admittedly after inexplicably saying that Hannibal ‘turned left’) actually states that Hannibal marched east along the Druentia (Durance) through the lands of the Tricastini.


Crossing the Alps
Many surveys of this issue try to build tables, mapping the characteristics of the various passes against the various events in Polybius’s and Livy’s accounts of Hannibal’s route.  Very clever people have spent their lives doing this, and have done so wonderfully detailed and clever ways.

However, out of all of these, I think there are two facts which I personally think are more critical than all the others:

• A 'panoramic' view of Italy (such as Hannibal pointed out to his troops) is only found on the Clapier and Traversette Passes.

and

• The ONLY pass in the Alps which has a double-landslide such as that described by Polybius is the Traversette Pass.

This strikes me as final.  These are the critical identifiable events of the journey over the Alps and there is only one Pass (two at best) which fits the bill.  And if any of those very clever people suggest that you haven't studied the issue enough and that their Pass fits better, surely the simple question is: 'Does your Pass have a double-landslide?'  And if their answer is 'No' (which is surely must be), then surely the only response is: 'Well then it doesn't fit, does it?'

There are other issues which are less decisive.  A number of passes have a steep descent into Italy.  A number of passes are high enough to have standing snow onto which new snow falls.  A number of passes have ‘white rocks’ and areas large enough for an army to camp.  But having reduced our options to two, all we need to know is that the Clapier and Traversette Passes fulfill all of these criteria as well.

A number of historians have puzzled over the story – which obviously gained popular currency in Roman times – of Hannibal clearing rocks by lighting a fire under them and pouring on vinegar. Just where these rocks were, however, is more of a mystery.  Mahaney found some rocks which were fire-burned in the Clapier Pass ... but when he investigated them, he found the burn-marks were not extensive enough, and probably came from a lighting-strike rather than a quarrying fire.  So what are we to make of this story?  Polybius did not mention it at all, and to be honest it probably fell into his category of ‘false statements’ made in ignorance.

So we are left with the feeling that Clapier is a good fit, but that Mahaney’s Traversette theory has a trump card in the double landslide.  
And thus it is probably possible to say that the Col de la Traversette most exactly fits Polybius’s account of Hannibal’s route.


The Ever-elusive Answer
But does that mean we have found the route which Hannibal took?

To think about this, I want to go back to Livy’s account of the fire-and-vinegar cracking of the boulders, and those fire-burned rocks in the Col de Clapier.  If the incident didn’t happen, how did the story become so current?  

I am reminded about the legend of Napoleon carving his name on some rocks he had decided were ‘Hannibal’s Rocks’, and indeed of other famous landmarks associated in legend with famous historical figures (such as King Charles’s Oak near Worcester).  Usually these associations are apocryphal, and simply an attempt to establish a famous historical link to get a bit of fame-by-association.  Recently there was an attempt to call the road between Veynes and Gap in southern France ‘the Hannibal Route’; it is very scenic and no doubt would delight the tourists … but, as we have seen, nobody has a clue which road Hannibal took to the Alps.

So where did that story of burning the rocks come from?  Is it not eminently possible that, crossing the Col de Clapier, people saw the burned rocks, and associated them (erroneously) with Hannibal ... and the story grew from there - that the rocks created the story, rather than the event producing the rocks?

However, if this is possible, what does that mean for our appreciation of Polybius’s account?  

William Mahaney has conducted a geo-chemical investigation of the Traversette Pass and established to his satisfaction that it is the Traversette Pass which best matches the account in Polybius.  (Or, if you prefer it, Patrick Hunt has walked the Col de Clapier, Polybius in hand, and marshaled his archaeological knowledge to claim that it is the Clapier Pass which best fits Polybius.)

But, in the 2nd century bc, wasn’t that exactly what Polybius was doing as well?  
We know that Polybius himself visited the historical scenes he was describing, and that his geographical knowledge was very carefully researched.  So he was doing exactly what Mahaney and Hunt have been doing – taking anecdotes and events about Hannibal’s crossing from Silenus and Sosylus and the various eyewitnesses-he-interviewed, and matching them to the route he thought best-matched.  
So we are not to be surprised that Polybius’s account fits an actual Pass … OF COURSE it fits an actual pass, because it was an actual pass he was describing when he placed his story of Hannibal’s crossing in its setting.

So, when Mahaney and Hunt best-guess they have found Polybius’s Pass, they have only found the Pass that Polybius best-guessed Hannibal used.  

I accept that this is probably the best we will ever do.
But it was not necessarily the Pass that Hannibal DID use.