The Second Punic War — also known to the Roman tradition as the Hannibalic War, after the Carthaginian general who commanded the principal Punic field forces throughout the conflict — was the military-political contest that the First Punic War had anticipated. It was prosecuted across the Italian peninsula, Iberia, Sicily, and the North African coast. The Roman Republic survived the near-destruction of its field armies at Trebia (218 BC), Lake Trasimene (217 BC) and Cannae (216 BC), maintained its alliance system with most of the Italian cities despite Hannibal's diplomatic efforts to detach them, and eventually defeated Hannibal at Zama in October 202 BC. The outcome was the reduction of Carthage to a regional power confined to the North African coast, the Roman acquisition of Iberia, and the establishment of the Roman Republic as the dominant military-political power of the Mediterranean.
Saguntum
The occasion of the war was Hannibal's siege of the city of Saguntum on the east coast of Iberia, beginning in May 219 BC. The Saguntine appeal to Rome for protection was based on a pre-existing diplomatic relationship; the Roman demand on Carthage that the siege be raised was refused; the Saguntine resistance to the Punic siege lasted eight months before the city's capture and sack in November 219 BC. The Roman declaration of war followed in spring 218 BC, after a period of diplomatic exchange in which the Carthaginian Senate refused the Roman demand for the surrender of Hannibal personally.
The strategic plans of both sides at the outbreak of war anticipated a war in Iberia and the Mediterranean. The Roman consular allocations for 218 BC sent one consul (Publius Cornelius Scipio, the father of the future Scipio Africanus) to Iberia with a army of approximately 22,000 troops and 60 ships, and the other consul (Tiberius Sempronius Longus) to Sicily with similar forces with the intention of an invasion of Africa. Hannibal's counter-plan was radical: the transfer of the Carthaginian field army from Iberia across the Pyrenees and the Alps into the Italian peninsula itself, with the intention of fighting the war on Roman home territory and breaking the Roman alliance system with Italian cities.
The Alps
Hannibal's march from New Carthage to the Italian Po valley between spring and autumn 218 BC was the logistical achievement of the ancient military tradition. The expedition began at New Carthage in May 218 BC with approximately 90,000 infantry, 12,000 cavalry, and 37 elephants. The crossing of the Pyrenees in late summer was uncontested but produced casualties; the crossing of the Rhone in the autumn was contested by local Gallic populations but completed by a improvised pontoon system. The crossing of the Alps — over a pass that has been the subject of two thousand years of historical-geographical argument, most credibly the Col du Clapier or the Col de la Traversette — occupied approximately fifteen days in late October and early November 218 BC, with losses from snow, avalanche, fighting with mountain peoples, and exhaustion. The expedition that emerged into the Po valley in mid-November numbered approximately 20,000 infantry, 6,000 cavalry and a small number of surviving elephants.
Trebia, Trasimene, Cannae
The three principal battles of the early phase of the war produced the near-destruction of the Roman field army in successive engagements. The Battle of the Trebia in December 218 BC — Hannibal's ambush of the consul Sempronius Longus's army on the frozen banks of the Trebia tributary of the Po — produced approximately 20,000 Roman casualties out of an engaged force of approximately 40,000. The Battle of Lake Trasimene in June 217 BC — Hannibal's ambush of the consul Gaius Flaminius's army in a defile along the north shore of the Trasimene lake — produced approximately 15,000 Roman dead and 15,000 captured out of an engaged force of approximately 30,000; Flaminius himself was killed. The Battle of Cannae on the 2nd of August 216 BC — the principal tactical achievement of Hannibal's career — produced approximately 50,000 Roman dead and 10,000 captured out of an engaged force of approximately 86,000.
The Cannae tactical pattern — Hannibal's double-envelopment of the Roman heavy infantry, with the Carthaginian centre withdrawing under pressure while the Punic and Numidian wings enveloped the Roman flanks and rear — has been the principal battlefield example studied by subsequent military theorists. The Roman casualty rate at Cannae — approximately 70% of the engaged force killed or captured — was the worst single-day loss in the Roman military tradition until the 1916 Somme.
Why Rome did not break
The Roman casualty rate at Cannae — approximately seventy per cent of the engaged force killed or captured — was the worst single-day loss in the Roman military tradition until the 1916 Somme.
The Roman state's response to the Cannae disaster defines the difference between the First and the Second Punic Wars. The First Punic War had been conducted between comparable powers; the Cannae catastrophe should, on the standard analysis of the Mediterranean military tradition, have produced Roman surrender or Roman political collapse. The Roman Senate's decision instead — mourning the dead, decreeing that no Roman citizen would weep publicly for them, refusing all diplomatic contact with Hannibal, reorganising the military on a new basis with larger forces, expanding the citizen body to increase the recruiting base — was the principal strategic-political fact of the war.
The Roman strategic adaptation after Cannae comprised four principal elements:
- Avoidance of pitched battles. The Fabian strategy — named for Quintus Fabius Maximus Cunctator ("the Delayer"), dictator in 217 BC — substituted harassment and logistical attrition for decisive engagement. Mocked in the immediate post-Cannae period; the principal Roman operational pattern for the subsequent twelve years.
- Extension to multiple theatres. The Iberian campaigns under the Scipio family progressively reduced the Punic position there; Sicily was recovered (including the siege and capture of Syracuse, 212–211 BC); Sardinia was held.
- Massive military expansion. By 212 BC the Roman state maintained approximately 25 legions — about 200,000 regular troops, plus larger numbers of allied Italian contingents.
- The Italian alliance system held. Most principal Italian cities remained loyal to Rome despite Cannae. Capua and the Greek cities of southern Italy were the exceptions, defecting to Hannibal in 216–211 BC.
Capua and Syracuse
The principal Italian defections to Hannibal — Capua in 216 BC and Tarentum in 213 BC — produced the principal Roman counter-operations of the subsequent years. The Roman siege of Capua from 212 BC produced the principal set-piece engagement of the middle period of the war; Hannibal's principal relief attempt in 211 BC — including a diversion against Rome itself, the famous incident of Hannibal encamping within sight of the walls of Rome ("Hannibal ad portas") — was insufficient to break the Roman siege. Capua fell to the Romans in 211 BC and was punished harshly. The parallel campaign in Sicily, conducted by the proconsul Marcus Claudius Marcellus, produced the siege and capture of Syracuse (whose famous defensive engines designed by Archimedes delayed but did not prevent the capture) in 212–211 BC.
The Iberian phase
The decisive theatre of the middle period of the war was Iberia, where the Punic position was eroded through the campaigns of the elder Scipios from 218 to 211 BC (both killed in 211) and won by the young Publius Cornelius Scipio (the future Scipio Africanus) from 210 BC onwards. The Scipionic reorganisation of the Roman Iberian forces, the capture of New Carthage in a daring operation in 209 BC, the Battle of Baecula in 208 BC and Ilipa in 206 BC, produced the expulsion of the Carthaginian forces from Iberia by 206 BC.
The loss of Iberia was the strategic catastrophe of the Punic war effort. The Iberian recruiting base, the Iberian silver, and the Iberian commercial network on which the Barcid economic position depended were all eliminated. Hannibal's position in southern Italy was reduced to a defensive enclave; the relief expedition of his brother Hasdrubal Barca, which crossed the Alps in 207 BC, was defeated and Hasdrubal killed at the Battle of the Metaurus in June 207 BC.
Hannibal in southern Italy
The sixteen years that Hannibal spent in the Italian peninsula (autumn 218 BC to autumn 203 BC, with the principal active campaigning concentrated in the early and late years) were the principal military achievement of the ancient world. The Carthaginian field force, detached from its home base, without reinforcement except for the failed Hasdrubal expedition, maintained itself in enemy territory for the period through tactical and diplomatic skill. The Roman field forces declined engagement throughout most of the period. By 203 BC the Carthaginian Senate had recalled Hannibal to Africa to defend Carthage itself against the Roman invasion that the Scipionic victories had made possible.
The concluding phase of the war — the Scipionic invasion of Africa, the Battle of Zama, and the 201 BC peace — is the subject of chapter VIII.
End of Chapter VII