But there during the brief interval a prodigious change had occurred. The Latin confederacy was broken and scattered, the last resistance of the Volsci was overcome, the province of Campania, the richest and finest in the peninsula, was in the undisputed and well-secured possession of the Romans, and the second city of Italy was a dependency of Rome. While the Greeks and Samnites were contending with each other, Rome had almost without a contest raised herself to a position of power which no single people in the peninsula possessed the means of shaking, and which threatened to render all of them subject to her yoke. A joint exertion on the part of the peoples who were not severally a match for Rome might perhaps still burst the chains, ere they became fastened completely. But the clearness of perception, the courage, the self-sacrifice required for such a coalition of numerous peoples and cities that had hitherto been for the most part foes or at any rate strangers to each other, were not to be found at all, or were found only when it was already too late.
After the fall of the Etruscan power and the weakening of the Greek republics, the Samnite confederacy was beyond doubt, next to Rome, the most considerable power in Italy, and at the same time that which was most closely and immediately endangered by Roman encroachments. To its lot therefore fell the foremost place and the heaviest burden in the struggle for freedom and nationality which the Italians had to wage against Rome. It might reckon upon the assistance of the small Sabellian tribes, the Vestini, Frentani, Marrucini, and other smaller cantons, who dwelt in rustic seclusion amidst their mountains, but were not deaf to the appeal of a kindred stock calling them to take up arms in defence of their common possessions. The assistance of the Campanian Greeks and those of Magna Graecia (especially the Tarentines), and of the powerful Lucanians and Bruttians would have been of greater importance; but the negligence and supineness of the demagogues ruling in Tarentum and the entanglement of that city in the affairs of Sicily, the internal distractions of the Lucanian confederacy, and above all the deep hostility that had subsisted for centuries between the Greeks of Lower Italy and their Lucanian oppressors, scarcely permitted the hope that Tarentum and Lucania would make common cause with the Samnites. From the Sabines and the Marsi, who were the nearest neighbours of the Romans and had long lived in peaceful relations with Rome, little more could be expected than lukewarm sympathy or neutrality. The Apulians, the ancient and bitter antagonists of the Sabellians, were the natural allies of the Romans. On the other hand it might be expected that the more remote Etruscans would join the league if a first success were gained; and even a revolt in Latium and the land of the Volsci and Hernici was not impossible. But the Samnites - the Aetolians of Italy, in whom national vigour still lived unimpaired - had mainly to rely on their own energies for such perseverance in the unequal struggle as would give the other peoples time for a generous sense of shame, for calm deliberation, and for the mustering of their forces; a single success might then kindle the flames of war and insurrection all around Rome. History cannot but do the noble people the justice of acknowledging that they understood and performed their duty.
Differences had already for several years existed between Rome and Samnium in consequence of the continual aggressions in which the Romans indulged on the Liris, and of which the founding of Fregellae in 426 was the latest and most important. But it was the Greeks of Campania that gave occasion to the outbreak of the contest. After Cumae and Capua had become Roman, nothing so naturally suggested itself to the Romans as the subjugation of the Greek city Neapolis, which ruled also over the Greek islands in the bay - the only town not yet reduced to subjection within the field of the Roman power. The Tarentines and Samnites, informed of the scheme of the Romans to obtain possession of the town, resolved to anticipate them; and while the Tarentines were too remiss perhaps rather than too distant for the execution of this plan, the Samnites actually threw into it a strong garrison. The Romans immediately declared war nominally against the Neapolitans, really against the Samnites (427), and began the siege of Neapolis. After it had lasted a while, the Campanian Greeks became weary of the disturbance of their commerce and of the foreign garrison; and the Romans, whose whole efforts were directed to keep states of the second and third rank by means of separate treaties aloof from the coalition which was about to be formed, hastened, as soon as the Greeks consented to negotiate, to offer them the most favourable terms - full equality of rights and exemption from land service, equal alliance and perpetual peace. Upon these conditions, after the Neapolitans had rid themselves of the garrison by stratagem, a treaty was concluded (428).
The Sabellian towns to the south of the Volturnus, Nola, Nuceria, Herculaneum, and Pompeii, took part with Samnium in the beginning of the war; but their greatly exposed situation and the machinations of the Romans - who endeavoured to bring over to their side the optimate party in these towns by all the levers of artifice and self-interest, and found a powerful support to their endeavours in the precedent of Capua - induced these towns to declare themselves either in favour of Rome or neutral not long after the fall of Neapolis.
A still more important success befell the Romans in Lucania. There also the people with true instinct was in favour of joining the Samnites; but, as an alliance with the Samnites involved peace with Tarentum and a large portion of the governing lords of Lucania were not disposed to suspend their profitable pillaging expeditions, the Romans succeeded in concluding an alliance with Lucania - an alliance which was invaluable, because it provided employment for the Tarentines and thus left the whole power of Rome available against Samnium.