approval of the gods was necessary and that with it Rome could not fail.
The third century was not only, as Polybius observed, the high point in the development of the Roman body politic; it also marked
the acme of the system of Italian alliances which Rome had built up, before the strains began to show. The last great Gallic invasion
which Italy had to face was that of 225, and it is in the context of the preparations against it that Polybius describes the manpower
resources available to Rome. To do so he drew on the account given by the first Roman historian, Q. Fabius Pictor, himself a
witness of the events of 225. Although the list in Polybius contains some obscurities in detail, it fits with what else is known of
Roman citizen numbers in this period and suggests that the Roman and Italian pool of men on which Rome could draw was of the
order of 6-7 million.
Hannibal's Invasion: The Second Punic War
The existence of such a reserve enabled Rome to withstand the shock of Hannibal's invasion of Italy in 218. This invasion, the
resources for which were provided by the Carthaginian acquisition of an empire in Spain, was a deliberate attempt to reverse the
verdict of the First Punic War. Between 218 and 216, Hannibal, a brilliant general, was able to inflict a series of crushing and
bloody defeats on the Roman armies sent to face him, culminating in the battle of Cannae in 216, and was able to detach a number
of Rome's allies, notably Capua; at the same time, Carthage attempted to recover Sicily and in due course brought Syracuse over to
her side.
But Rome was always able to field new armies to replace those which were lost, and most of her Italian allies never regarded Italy
without Rome or Italy under Carthage as serious alternatives to the system with which they had become familiar. Rome first
succeeded in confining Hannibal to Bruttium, while simultaneously recovering Sicily, seizing Spain, and fighting against
Macedonia, which had allied with Carthage in 215 after the battle of Cannae. In due course the war was carried over to Africa;
Hannibal was recalled from Italy in 203, to be defeated at the battle of Zama in 202; Carthage sued for peace and the attempt to
dispute Roman hegemony in the western Mediterranean was over.
Hannibal's Legacy
What were the effects on Italy of fifteen years of warfare on Italian soil? It has been argued that the devastation of much of Italy by
Hannibal led to the deracination of many Roman and Italian peasant soldiers and a shift to large farming enterprises owned by the
elite and run by slave labour; whence the problems which Ti. Gracchus set out to resolve two generations later (below, pp. 411 f).
The argument is hard to maintain. Rome not only continued to field large armies of peasant soldiers throughout the Second Punic
War, but undertook after it was over both the final conquest of the Po valley and a series of wars overseas (below, ch. 17).
For those Italian communities that had allied with Hannibal, however, the consequences of his defeat were grave. The Bruttii were
deprived of any form of communal institutions and were not even allowed a role in the armies levied by Rome, except as servants.
They and many other communities lost land, a fact which lies behind some of the economic developments of the second century.
Those communities which continued to provide troops for Rome were forced to provide disproportionately large contingents. In
effect, if not in theory, second-century Italy was a single state ruled by Rome, with local government in the hands of its scattered
communities, not a mosaic of independent states bound together by a network of alliances.
The principal Roman military effort in Italy after 201 was directed to the definitive conquest of the Po valley. The process had
begun after the defeat of the Gallic invasion of Italy in 225, with the foundation in 218 of the coloniae of Cremona and Placentia.
Rome picked up after the Second Punic War where she had left off, and the next generation saw both the military subjugation of the
area and the settlement, either in coloniae or in scattered plots, of tens of thousands of Romans and Italians, from Placentia in the
west to Aquileia in the east. Of the different Gallic peoples, the Boh simply ceased to exist, as had the Senones earlier. The
Cenomani and Insubres survived, albeit with their freedom gone.
Both the nature of the landscape and the unfolding of the Roman conquest help to explain why Gallia Cisalpina is the area
characterized more than any other by Roman centuriation (above, p. 400). As they moved across the largest plain in Italy, the
Romans felt themselves bound by no existing political, social, economic, or even geographical pattern. A tabula rasa, the Po valley
was imprinted for ever with the marks of the Roman presence, and absorbed over a whole generation much of the military and
colonizing energy of the Roman people, energy which appears undiminished by the experience of the Second Punic War.