New study calculates the most likely route of Hannibal's crossing of the Alps

Calculations on the animals' energy requirements

Calculations of the energy requirements of the journey, particularly for the war elephants, point to the Col de la Traversette as the most favorable route for the commander and his baggage train. The animals required, according to the study, considerable amounts of food and water, which is likely to have played a central role in the choice of pass.

Hannibal's crossing of the Alps with elephants is regarded as one of the most famous military feats of antiquity. In 218 BC, the Carthaginian commander led his army across the Alps to attack the Romans in Italy. The exact route of the army has been the subject of historical and geographical debate for centuries.

The Col de la Traversette lies in the Cottian Alps at an altitude of around 2,950 meters. The pass connects the French département of Hautes-Alpes with the Italian region of Piedmont. Its geographic location makes it a historically plausible corridor between the Rhône Valley and the Po Plain.

The Col de la Traversette as a candidate

The iDiv research group combined geographic data with models of elephants' energy consumption under Alpine conditions for its analysis. Factors such as gradient, distance, available grazing land, and climatic conditions in the autumn of 218 BC were taken into account.

The study joins a long line of attempts to reconstruct the exact course of the Alpine crossing. Earlier works had proposed, among others, the Little St. Bernard, the Great St. Bernard, and the Col du Mont Cenis as possible routes. Most of these proposals relied, however, primarily on ancient written sources, above all the account of the historian Polybius.

The new analysis supplements these text-based approaches with quantitative calculations and, according to iDiv, thereby provides an additional argument for the Traversette route. The researchers emphasize, however, that other passes cannot be ruled out either and that further studies are needed.

Open questions in research

Historians have long debated how many elephants Hannibal actually led across the Alps. While ancient sources sometimes give the number in the dozens, more recent research tends to assume just a few animals. This factor too significantly influences the calculations of energy requirements.

The study was published by iDiv in Leipzig and presented to the public on Monday evening. The Center for Integrative Biodiversity Research is a research institution that deals with questions of biodiversity and ecosystem research and operates at several locations in central Germany.

The findings could also be relevant beyond the discipline of history. They show how scientific models and historical sources can complement each other to better understand events far in the past.