The Battle of Cannae, 216 BC - The Role of Citizen Soldiers

In Southeast Italy a battlefield near Cannae served as the scene where Rome would suffer its greatest defeat in all of its history. Though the Roman soldiers used superior weapons and greatly outnumbered the mercenary army of Carthaginian general Hannibal Barca by nearly double, the strategic brilliance of Hannibal allowed his numerically inferior army to obliterate the Roman legions. Coming during the Second Punic War on August 2^nd, 216 BC the Battle of Cannae failed to affect the outcome of the entire war, where Roman troops would eventually overrun Hannibal's army. The battle does, however, serve a few significant points in Western military history. After the Roman legions were completely annihilated with most of its troops captured or killed, the Roman military went through drastic reforms that would keep them from being significantly defeated for the next few centuries. The second significance of the Battle of Cannae was an example of civil militarism put into action by the Roman Republic.

Hannibal's mercenary army consisted of Spaniards, barbarians from Gaul and even (and most decisively) mercenaries from Northern Africa. The ill-fated Romans fell into Hannibal's trap, with his military brilliance calling for the heavily armed infantrymen from Northern Africa to outflank the Roman troops. The Roman legions were set up so that it was made impossible for them to outmaneuver a surprise attack from the side, and before long the Italians were surrounded and the army was torn apart. Due to this weak military tactic, the Roman military doctrine underwent various changes. Instead of command of the armies coming from two different sources, each of the Roman Republic's consuls, the Roman legions were brought under a unified command. The internal renovation that the Roman army went through allowed the legions to be commanded by a single commander-in-chief instead of two consuls (who might not have any tactical brilliance themselves), where fighting under two commanders lacked consistency and stability in their military tactics.

The tactical organization of the Roman army also changed. When the Greek phalanx was used at the Battle of Cannae it became impossible for the Roman legions to maneuver out of Hannibal's trap and they could not counter-attack. Instead of rows of phalanxes, the legions were instead split up into columns and were in small military bodies instead of a large mass of troops, making them easier to command and to maneuver during battle. Though countless Italian soldiers lost their lives during the Battle of Cannae, they were replaced with an unprecedented quickness. Each of the soldiers in the army was a "citizen soldier", some of which were fully free in the Roman Republic and others who had partial citizenship. Because mercenary tribes from Gaul, Persia, Africa, and Spain were not a single entity (a "nation in arms") after troops were initially scrounged up there was little reinforcements that could come. Often going to the highest bidder, these mercenary bands could also prove quite costly unlike the citizen soldiers of Rome. After Cannae, more Roman subjects came up in arms to protect their own homeland. All citizens, down to the farmer who was barely a part of the Republic, were expected to follow in their ancestor's footsteps (and they did) to repel and destroy the enemies of Rome. They did just that, for in the coming years they would drive Hannibal from the Italian peninsula and demonstrate the power of a nation of soldiers over a multinational mercenary army.

Source:

College Level lecture

Carnage and Culture by Victor Davis Hanson.