In 216 BCE, Roman military tactics were still in their infancy. Although Rome had won many impressive victories during the First Punic War, they continued to rely on their old tactic of placing a numerically superior force in the field to overwhelm the enemy. The typical Roman formation was to position light infantry toward the front masking the heavy infantry and then coordinating light and heavy cavalry on the back wings. This formation had worked well in Rome’s wars with the Greek King Pyrrhus who, although victorious at the Battle of Asculum (279 BCE), lost so many men that his army could not continue on to take the city. Pyrrhus used much the same strategy as the Romans did: he would place a large force in the field and rely on the superior numbers and the charge to break the Roman ranks. At the Battle of Cannae in 216 BCE, however, the Romans would learn an important lesson in military strategy from a general who fought like no other had before him.
Hannibal's Skills & Rome's Response
The Carthaginian general Hannibal started the Second Punic War when he attacked the city of Saguntum, a Roman ally, in southern Spain in 218 BCE. He then invaded northern Italy by marching his army across the Alps from Spain. Once descended onto the plains, he began advancing through Roman territory taking small cities and villages and defeating Roman forces twice; once at Trebia, at the Ticino River, and again at Lake Trasimene. By 217 BCE, Hannibal held all of northern Italy and the Roman senate feared he would march upon Rome. Little was being done, they felt, by the consul Quintus Fabius Maximus, who controlled the army and was following a policy of harassing Hannibal and thwarting his plans through strategic movements rather than full engagement.
In 216 BCE the consul Minucius Rufus was elected to command with Fabius and called for direct confrontation with the invading Carthaginian army. He was swiftly defeated by Hannibal who used tactics which the Roman command could not understand until it was too late. According to the historian Durant, “The Romans could not readily forgive him [Hannibal] for winning battles with his brains rather than with the lives of his men. The tricks he played upon them, the skill of his espionage, the subtlety of his strategy, the surprises of his tactics were beyond their appreciation” (48). With the defeat of Rufus, Rome scrambled to mobilize another force to take the field.
The Battle at Cannae
The two consuls Lucius Aemilius Paulus and Caius Terentius Varro led a force of over 50,000 against Hannibal’s less than 40,000 and met him in battle at Cannae. Hannibal disguised his intentions by placing his light infantry of Gauls at the front to mask his heavier infantry whom he positioned in a crescent formation behind them. At a given signal just before battle, the light infantry fell back to form two wings of reserves. Hannibal’s light and heavy cavalry were positioned at the extreme wings of the position. The Romans, following their usual understanding of battle in which superior forces would overwhelm by sheer strength, arrayed their forces in traditional formation with light infantry masking the heavier and the cavalry also to the wings.
When the Roman legions began their march toward the Carthaginian lines, the Carthaginian infantry fell back before them. The Romans took this as a positive sign that they were winning and pressed on. The Carthaginian light infantry, who had earlier fallen back, now took up position on either end of the crescent formed by their heavy infantry. At this same time the Carthaginian cavalry charged the Roman cavalry and engaged them. The Roman infantry continued their charge into the enemy’s ranks but, precisely because of their traditional formation, could make no use of their superior numbers. Those soldiers toward the back of the ranks merely served to push those before them onward. At the same time, the Carthaginian heavy cavalry drove back the Roman cavalry, opening a breach in the lines to the rear of the infantry. As the cavalry forces engaged, and as the Roman infantry continued its advance, Hannibal signaled for the trap to close. The light infantry which formed the ends of the crescent of the Carthaginian line now moved up to form an alley in which the Roman forces found themselves trapped. The Carthaginian cavalry fell upon the Roman infantry from behind, the light infantry attacked from the flanks, and the heavy infantry engaged from the front. The Romans were surrounded and were almost completely annihilated. Out of the over 50,000 who took the field, 44,000 were killed and 10,000 managed to escape to Canusium. Hannibal lost 6,000 men, mostly the Gauls, who had made up the front lines.
According to Durant, “It was a supreme example of generalship, never bettered in history. It ended the days of Roman reliance upon infantry and set the lines of military tactics for two thousand years” (51). Among those Romans who escaped Cannae was the twenty-year old Publius Cornelius Scipio. Scipio would remember Hannibal’s tactics at Cannae and, further, would study his other successful engagements. Fourteen years later, at the Battle of Zama in 202 BCE, Scipio would use Hannibal’s own tricks to defeat him and win the Second Punic War. Roman skill on the battlefield, through which they became masters of the world, can be traced directly back to Scipio Africanus and his adaptations of Hannibal’s strategies at Cannae.