War broke out between them and their captain, who had come amongst them a hired mercenary and now appeared desirous to found a Hellenic empire in the west like his nephew in the east.
Alexander had at first the advantage; he wrested Heraclea from the Tarentines, restored Thurii, and seems to have called upon the other Italian Greeks to unite under his protection against the Tarentines, while he at the same time tried to bring about a peace between them and the Sabellian tribes.

But his grand projects found only feeble support among the degenerate and desponding Greeks, and the forced change of sides alienated from him his former Lucanian adherents: he fell at Pandosia by the hand of a Lucanian emigrant (422).( 1) On his death matters substantially reverted to their old position.

The Greek cities found themselves once more isolated and once more left to protect themselves as best they might by treaty or payment of tribute, or even by extraneous aid; Croton for instance repulsed the Bruttii about 430 with the help of the Syracusans.

The Samnite tribes acquire renewed ascendency, and were able, without troubling themselves about the Greeks, once more to direct their eyes towards Campania and Latium.
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.