Hannibal, Rome's adversary during the Second Punic War, was, along with Alexander, the greatest warlord of antiquity. What were the nature and limits of his military talent? We can try to give some answers after having recalled the main lines of his career.

During the Second Punic War (218-202 BC), Hannibal's strategic goal was to break the Italian confederation, that is, to separate Rome from its allies. To achieve this goal, Roman military power had to be destroyed. Leaving Cartagena in 218, he crossed the Iberian Peninsula, the Rhone and the Alps, and accumulated tactical victories: in Ticino and Trebia (218), and especially in Trasimeno the following year. This battle, which took place as a superior form of ambush, caused 15,000 deaths on the Roman side. In accordance with his objectives, Hannibal ordered the massacre of the Romans and spared the other Italians.

In the face of Hannibal's tactical superiority, Rome realized that it was necessary to avoid confrontation in the open field in favor of an indirect strategy using harassment tactics to limit casualties and buy time to rebuild its forces. Rome gave up too soon and sought a frontal encounter. It took place in Cannes in 216. The Roman legions were annihilated, but the battle was not decisive: Hannibal, for uncertain reasons, did not march on Rome.

The Romans finally found, in the person of Scipio, a general capable of facing Hannibal. Scipio, inspired by the lessons of the Punic leader, developed new tactics which he experimented in Spain, where he defeated Hannibal's brother Hasdrubal at the battle of Baecula (208). The light infantry attacked in the center, the heavy infantry attacked in pincers: the lessons of Cannes had been learned. Scipio could then hope to defeat Hannibal himself. He organized the offensive by bringing the war to Africa in order to force Carthage to recall Hannibal. It was also a way to force the enemy into battle. The meeting took place in Zama in 202, a decisive battle where Carthage lost its military instrument and was forced to negotiate.

About fifteen ancient authors form the corpus of sources on the Second Punic War. But from a military point of view, one author stands out, namely Polybius (between 210 and 208 - 126 BC). Born in Megalopolis in Arcadia, Polybius held both political and military positions in the Achaemen League. He is also the author of a Treatise on Tactics, now lost, but which had a good reputation in its time. Sent to Rome as a hostage after the Macedonian defeat of Pydna against the Romans (168), he was welcomed by the great Scipio family and befriended Scipio Emilian, whom he accompanied during the siege of Carthage. This position gave him access to many historical sources, and his military skills give his battle accounts a particular precision and rigour.

Whether Hannibal was as much a strategist as he was a tactician is a matter of broader historiography and, to some extent, the debate is not closed. The prevailing tendency is to praise the tactician and point out that he failed to exploit his tactical successes. This would be summed up by the famous phrase that Livy the Great lent to Maharbal, the leader of the Numidian cavalry, after Hannibal's refusal to march on Rome: "You know how to defeat Hannibal, but you don't know how to take advantage of your victory". Polybius does not mention this episode, probably invented and very much in the style of Titus Livius, who always favours the ideological component in warfare: where the Roman stands out from the Barbarian. The latter is always presented as subject to inconsistency in victory and discouragement in failure. This is what is called a topos, that is, an ideological commonplace.

If Hannibal did not exploit his Cannes victory, it was probably not out of pusillanimity. The city was well defended by strong walls, Hannibal lacked siege machines, and the Punic army, formidable in a context of mobility, was not very fit to conduct a siege, as were most mercenary armies.

Nevertheless, Hannibal's strategic objective of separating Rome from its allies was not achieved. But that doesn't mean we can consider him a bad strategist. On the one hand, his attack on Italy from the north remains historically a model of "blitzkrieg" and, on the other hand, Hannibal did have a strategic goal articulated with tactical objectives. The fact that he systematically spared Rome's allies at the end of a battle bears witness to this.

If we return to the tactical register, we can try to identify the style of the Punic leader through two examples, that of Cannes, his greatest victory, and that of Zama, his final defeat.

It was on the plain of Cannes, in 216 B.C., that Hannibal elaborated what history considers his masterpiece. The Romans committed considerable forces: almost 80,000 infantrymen and 6,000 cavalrymen against the Carthaginian army, which was 40,000 infantrymen and 10,000 cavalrymen strong. The legions deployed, cavalry on the wings, with a strong center, in accordance with the usual Roman tactic of breaking through the enemy's center. The Carthaginian set-up was the opposite, with strong wings (infantry and cavalry) and a weak center, consisting of infantry in thin lines, arranged in a convex arc over the opponent.

The battle was fought in three phases. The first saw the confrontation of light infantry and cavalry. The Carthaginian cavalry drove the Roman cavalry off the battlefield. In a second phase, Roman heavy infantry, the legion, attacked the Carthaginian center. The Carthaginian center, designed to give way, bent, reversing its curvature, then retreated without breaking, sucking the legions into the vice of the wings. In a third phase, the Roman army was surrounded and destroyed.

Through Polybius' description, Hannibal's device is presented as a mechanical trap: "Thus the Romans, driving back their opponents and converging towards the center of the enemy front, which gave way under their pressure, moved so far forward that they found themselves wedged between the two African heavy infantry corps massed on their flanks. The Africans on the right then turned a quarter turn to attack on the left and those on the left turned a quarter turn to attack on the right. The situation itself told them what they had to do" (emphasis added). Hannibal's maneuver is not presented as a succession of movements, adapting each time to the opponent's reaction, but as a device, which, once set up, works like a machine. The different sequences of the manoeuvre seem to be carried out successively by themselves, through the effect of the adverse action. And when the trap closes, according to Polybius, it is not on command: it is, he says, "the situation itself" that infers the movement of the fighters placed on the wings.

One finds a comparable idea of maneuver in the device developed by Hannibal at Zama in 202 BC. What first characterizes this battle is that the Numidians, whose cavalry had played a fundamental role at Cannes, had passed to the Roman side. Their leader, Massinissa, brought to Scipio 6,000 infantry and, most importantly, 4,000 cavalrymen who joined the 23,000 legionnaires and 1,500 Roman cavalrymen. Facing Scipio's forces, Hannibal lined up 36,000 infantrymen, few horsemen, and 80 elephants.

In this situation, Hannibal's concern was to neutralize the opposing cavalry without taking the risk of facing Massinissa. He thus ordered his cavalry to resist the Roman cavalry only weakly, and then to stall and drive it as far away as possible. Meanwhile, a trap had to work.

Behind the elephant screen, Hannibal had deployed his device in three lines. The first was made up of the brave but undisciplined mercenaries. The second was made up of the Carthaginian citizens, motivated but poorly trained. The last, the largest and most extensive, included the veterans of Italy, the elite of his army. The first two lines were designed to give way gradually and, in so doing, they were to exhaust the Roman legions, which, at the end of their advance, would come up against the last and longest line of veterans, which could then envelop them. According to historian Giovanni Brizzi, a specialist on Hannibal, the Punic leader had foreseen that the first two lines, by retreating, would gradually strengthen the last one, thus increasing its enveloping capacity. If Brizzi's hypothesis corresponds to reality, Hannibal's device at Zama was at least as ingenious as the one at Cannes.

The elephants' charge had no effect: they were channelled through corridors established by Scipio, without creating any damage. The Roman cavalry went into action and was taken away, according to Hannibal's instructions. It was then necessary to act quickly. As Hannibal had hoped, after the neutralization of the elephants, which stimulated Roman zeal, the legions went on the offensive. The first line gave way as planned, not without disorder. The legions continued to advance, but Scipio, a good student of Hannibal's, sniffed out the trap. He stopped his army, waited for the return of his cavalry, which, after driving off the Carthaginian cavalry, returned, took Hannibal's army from behind, and consummated the Punic defeat.

Hannibal's military genius would therefore be quite specific. He is not presented by the sources as the man of the eye, the one who seizes the right moment in a battle to engage the action of a formation, one of the qualities attributed to Alexander. Hannibal is said to be the man of the device: he develops a mechanism in which the behaviour of the actors is expected. Each time, the mechanism infers the manoeuvre. This is at least what emerges from Polybius' account. But the Greek historian seems fascinated by technology, as evidenced by the precision with which he describes the machines invented by Archimedes during the siege of Syracuse by Marcellus. Would Polybius have thus accentuated the mechanical aspect of Hannibal's devices? We will never know.