Hannibal Crosses the Alps

Charles Joseph Minard’s most famous work, a chart of Napoleon’s invasion of Russia, immediately impresses the observer with the magnitude of Napoleon’s losses.  The quickest of glances shows the dramatic thinning of the line representing the number of men in his army as they succumbed to starvation, enemy combat, and the bitter cold.  Minard produced a companion map, shown above, of Hannibal Barca’s invasion of Italy in 218 BC during the Second Punic War, including his famous crossing of the Alps.

Minard’s map charts Hannibal’s path from Iberia (Spain), across southern Gaul (France), across the Alps and into Italy.  Minard represents the number of men in Hannibal’s army with the thickness of the line showing the army’s path.  One millimeter of thickness represents 1,000 men.  The Hannibal map, however, is not as striking as the Napoleon map.  For one, the numbers of men involved in Hannibal’s invasion are significantly smaller.  Minard could have exaggerated Hannibal’s losses by increasing the ratio of men to line thickness, but held exactness in too high a regard to attempt such data manipulation.  Click here or on the picture above to see the full map.

The Punic Wars were fought between Rome and Carthage over control over the Western Mediterranean.  The First Punic War, between 264 to 241 BC, was fought over control of Sicily and ended with Roman victory and the defeat of Carthaginian naval power.  The Second Punic War, on the other hand, was fought over conflicting spheres of Roman and Carthaginian influence in Spain.  Rome declared war on Carthage in 218 BC, and Hannibal set out soon after to invade Italy.

Hannibal understood that Carthaginian naval power was weak, and that Rome had to be struck directly in order to guarantee decisive victory.  Since he had no means of attacking by sea, he had to strike overland.  According to Minard’s sources, Hannibal began his journey with 94,000 men including cavalry, siege engines, and, famously, 36 war elephants.  When he arrived at the Pyrenees, the force numbered about 80,000.  In the Pyrenees he subdued the local tribes with significant losses.  Minard records Hannibal’s army at a strength of 60,000 when it emerged from the mountains, a loss of 25%. 

An approximate overlay of Hannibal’s route on a modern-day map from Google Earth. Click on the picture to enlarge.

Hannibal now marched across the plains of southern Gaul, defeating or negotiating with the local tribes.  He only met significant resistance when he tried to cross the Rhone River near modern Avignon.  He defeated the opposing tribe, as Minard shows, by sending a detachment upriver and outflanking them.   Hannibal then began his crossing of the Alps.  To this day, Hannibal’s path across the mountains is debated.  Minard’s legend indicates that he uses the route suggested by French historian Jean-Louis Larauza, though Minard indicates he himself cannot speak to the historical accuracy of this route.  Regardless, Minard indicates the severe losses Hannibal’s army experienced during the crossing–46,000 men entered the foothills of the Alps in 218 BC, but only 25,000 emerged. 

Now in Italy, Hannibal sought to join up with anti-Roman allies in the region, but before he could he had to fight his way through further hostile tribes and local Roman forces.  By the time the army crossed the Po River, these engagements dwindled the forces to a stunning 6,000 men.  It was these few who would join with the anti-Roman forces in northern Italy to begin the main assault on Roman territory. 

Hannibal’s crossing of the Alps is generally regarded as a masterpiece of military strategy, but in the crossing Hannibal suffered dramatic losses of men, as well as of his war elephants and, perhaps most importantly, his siege engines.  Without these engines, Hannibal would not be able to penetrate the fortifications of Rome itself and force a surrender.  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.”  The constant skirmishes caused Hannibal’s limited manpower to dwindle to dangerous levels, and eventually forced his retreat as he still could not receive reinforcements from Carthage.