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The Orbis Encyclopedia · Event · 216 BC

Battle of Cannae

Hannibal's 216 BC masterpiece, where an outnumbered Carthaginian army encircled and annihilated a larger Roman force, the textbook double envelopment.

A tactical map of the Battle of Cannae showing Hannibal's blue Carthaginian infantry and cavalry encircling the red Roman army in a double envelopment along the Aufidus River, titled "The Battle of Cannae, 216 B.C., Destruction of the Roman Army."
Frank Martini, Cartographer, Department of History, United States Military Academy; SVG version by Wikimedia user Hogweard. Public domain.

On a single August day in 216 BC, Hannibal destroyed the largest army Rome had ever put in the field. Livy counted roughly 48,000 Roman dead (45,500 foot and 2,700 horse), the Greek historian Polybius closer to 70,000; either way, Hannibal killed roughly as many men in one afternoon as the United States lost in the whole of the Vietnam War. Cannae is why staff colleges still teach a battle fought more than two millennia ago. It is the textbook case of the smaller army winning by wrapping itself around the larger one.

The trap

Rome came to Cannae, on the Apulian plain of southeastern Italy, determined to crush Hannibal by sheer weight. The two consuls, the cautious Aemilius Paullus and the aggressive Terentius Varro, fielded around 80,000 men against Hannibal's 50,000. Hannibal turned that superiority into a weakness. He drew his army into a crescent that bulged toward the Romans, its center held by his least reliable Gauls and Spaniards, his hardened African infantry set back on the wings. As the dense Roman column drove into the center, the crescent slowly gave way and inverted, drawing the Romans deeper into a shrinking pocket. Meanwhile Hannibal's superior cavalry shattered the Roman horsemen on both flanks, rode around the rear, and slammed the door. The Romans were now surrounded, packed so tightly that many could not raise their swords, and were cut down where they stood. The maneuver, a simultaneous attack on both flanks and the rear, is the classic double envelopment.

Why it did not end the war

The dead included the consul Paullus and scores of senators, a generation of Rome's leadership erased in an afternoon. By any normal logic of the ancient world, Rome should have sued for peace. It refused. Instead the Senate embraced what became known as the Fabian strategy, after the general Fabius Maximus: avoid pitched battle, shadow Hannibal, cut off his supplies, and let time and Rome's deeper reserves of manpower grind him down. Hannibal won more battles but could not win the war. He roamed Italy for over a decade without taking the city, was eventually recalled to defend Carthage, and lost decisively to Scipio at Zama in 202 BC. The perfect battle had not produced a perfect outcome.

The dream of a Cannae

And yet Cannae became an obsession. Because it did what commanders forever dream of, the total encirclement and annihilation of an enemy, it turned into the holy grail of tactics. The German chief of staff Alfred von Schlieffen studied it fanatically and wrote a whole book on it, hoping to engineer a modern Cannae against France. Generals from the world wars to the Gulf War have chased the same vision, and military academies still dissect Hannibal's crescent on the board. Twenty-two centuries on, a Cannae remains the word soldiers use for the flawless victory that almost never comes.

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