As usual for ancient events, we are limited in the number of sources recording eye-witness observations. That anything exists after over 2,000 years is amazing in itself, but sadly, just about everything is lost to us, though we know of contemporary authors because they are quoted in histories compiled years later. Some archeological evidence has been unearthed, and there is a matching of the geological and geographical descriptions mentioned by the ancient authors. It is, of course, still a considerable amount of guesswork, hence the continuing and conflicting ideas about the actual route.

Socilos (also Socylos) was a Greek who taught the Greek language to Hannibal and later wrote a biography of Hannibal. The biography is lost, but referenced by Polybios. Silenos (also Silenus) was a Greek who accompanied the Carthaginian army and later wrote an "official history" of sorts. His writings were translated by Lucius Coelius Antipater, who in turn is quoted by Livy and Cicero. Of the history, it is lost, but, again, referenced. Lucius Cincius Alimentus was a Roman prisoner who learned of troop losses allegedly from Hannibal. He wrote no book, but is quoted by Livy. Polybius originally wrote 40 books on the history of the Rome circa 220-145BC, but most are lost. However, volumes I-V survive complete, much of VI, and fragments of the rest. As for this particular topic, he made a journey over the Alps approximately 60 years after Hannibal's crossing.

Livy [Livius] wrote an astounding 142 volume history, of which only 35 survive, including 10 on the Second Punic War (Books 21 to 30). His description of events is, at times, suspect, but voluminous and dramatic.

The later Roman historian Ammianus Marcellinus quotes Timagenes regarding various tribal information. Silius Italicis is a poet, not historian per se, but his work can be used to double check Livy on occasion. There is Appian, a generally unreliable historian. Various fragments survive: the letter from Servius, Strabo's Geography contains a passage regarding the location and identity of passes. Varro also offers a passage regarding the location and identity of passes. Gaditanian vases offer visual scenes. The Antonine Itinerary (2nd-3rd Century AD) describes routes from Gap to Leon as well as from Arles to Terragona.

These sources offer a glimpse into the moves of Hannibal during the autumn and winter of 218BC when the Carthaginian commander led his forces out of Spain and into Italy. They also offer tantalizing details of the march which should, in theory, be relatively straightforward to match to today's geographical features. It all boils down to reconstructing the route by reconciling time, distance, and geological features.

Alas, one scholar's perfect ambush spot in a gorge is another's geological impossibility, and one river can duplicate much of the same distance information as another. Indeed, one modern author contends the ancient historians count days from the last "event," rather than consecutively, which adds days and thus, the radius of possible pass sites. Another contends that copying errors through the last two millennia insert different meanings to key places and events. Nevertheless, to start Hannibal's march is to start with our two most available sources: Polybius and Livy.

Hannibal Crosses the Alps A Route Examined and a Proposed Alternate Route

Introduction
The Sources
Hannibal's March: Polybios and Livy
Polybios vs. Livy: Debate Over Details
A New Route Proposed: Begin at the End
A New Route Proposed: Start at the Beginning
A New Route Proposed: Where is the Druentia?
A New Route Proposed: The Pass in the Alps
Aftermath, Conclusion, and Bibliography