The Tarentines since the treaty of 450 [303 BC] had lived at peace with Rome. They had been spectators of the long struggle of the Samnites, and of the rapid extirpation of the Senones; they had acquiesced without remonstrance in the establishment of Venusia, Atria, and Sena, and in the occupation of Thurii and of Rhegium. But when the Roman fleet, on its voyage from the Tyrrhene to the Adriatic Sea, now arrived in the Tarentine waters and cast anchor in the harbor of the friendly city, the long, cherished resentment at length overflowed. Old treaties, which prohibited the war-vessels of Rome from sailing to the east of the Lacinian promontory, were appealed to by popular orators in the assembly of the citizens. A furious mob fell upon the Roman ships of war, which, assailed suddenly in a piratical fashion, succumbed after a sharp struggle; five ships were taken and their crews executed or sold into slavery; the Roman admiral himself had fallen in the engagement. Only the supreme folly and supreme unscrupulousness of mob-rule can account for those disgraceful proceedings. The treaties referred to belonged to a period long past and forgotten; it is clear that they no longer had any meaning, at least subsequently to the founding of Atria and Sena, and that the Romans entered the bay on the faith of the existing alliance; indeed, it was very much their interest—as the further course of things showed—to afford the Tarentines no sort of pretext for declaring war. In declaring war against Rome—if such was their wish—the statesmen of Tarentum were only doing what they should have done long before; and if they preferred to rest their declaration of war upon the formal pretext of a breach of treaty rather than upon the real ground, no further objection could be taken to that course, seeing that diplomacy has always reckoned it beneath its dignity to speak the plain truth in plain language. But to make an armed attack upon the fleet without warning, instead of summoning the admiral to retrace his course, was a foolish no less than a barbarous act—one of those horrible barbarities of civilization, when moral principle suddenly forsakes the helm and the merest coarseness emerges in its room, as if to warn us against the childish belief that civilization is able to extirpate brutality from human nature. And, as if what they had done had not been enough, the Tarentines after this heroic feat attacked Thurii, the Roman garrison of which capitulated in consequence of the surprise (in the winter of 472-473 [281-280 BC]); and inflicted severe chastisement on the Thurines—the same, whom Tarentine policy had abandoned to the Lucanians and thereby forcibly constrained into surrender to Rome—for their desertion from the Hellenic party to the barbarians.

The barbarians [Romans], however, acted with a moderation which, considering their power and the provocation they had received, excites astonishment. It was in the interest of Rome to maintain as long as possible the Tarentine neutrality, and the leading men in the senate accordingly rejected the proposal, which a minority had with natural resentment submitted, to declare war at once against the Tarentines. In fact, the continuance of peace on the part of Rome was proffered on the most moderate terms consistent with her honor—the release of the captives, the restoration of Thurii, the surrender of the originators of the attack on the fleet. A Roman embassy proceeded with these proposals to Tarentum (473 [280 BC]), while at the same time, to add weight to their words, a Roman army under the consul Lucius Aemilius advanced into Samnium. The Tarentines could, without forfeiting aught of their independence, accept these terms; and considering the little inclination for war in so wealthy a commercial city, the Romans had reason to presume that an accommodation was still possible. But the attempt to preserve peace failed, whether through the opposition of those Tarentines who recognized the necessity of meeting the aggressions of Rome, the sooner the better, by a resort to arms, or merely through the unruliness of the city rabble, which with characteristic Greek naughtiness subjected the person of the envoy to an unworthy insult. The consul now advanced into the Tarentine territory; but instead of immediately commencing hostilities, he offered once more the same terms of peace; and, when this proved in vain, he began to lay waste the fields and country houses, and he defeated the civic militia. The principal persons captured, however, were released without ransom and the hope was not abandoned that the pressure of war would give to the aristocratic party ascendency in the city and so bring about peace. The reason of this reserve was that the Romans were unwilling to drive the city into the arms of the Epirot king. His designs on Italy were no longer a secret. A Tarentine embassy had already gone to Pyrrhus and returned without having accomplished its object. The king had demanded more than it had powers to grant. It was necessary that they should come to a decision. That the civic militia knew only how to run away from the Romans, had been made sufficiently clear. There remained only the choice between a peace with Rome, which the Romans still were ready to agree to on equitable terms, and a treaty with Pyrrhus on any condition that the king might think proper; or, in other words, the choice between submission to the supremacy of Rome, and subjection to the—tyrannis—of a Greek soldier.

The parties in the city were almost equally balanced. At length the ascendency remained with the national party—a result, that was due partly to the justifiable predilection which led them, if they must yield to a master at all, to prefer a Greek to a barbarian, but partly also to the dread of the demagogues that Rome, notwithstanding the moderation now forced upon it by circumstances, would not neglect on a fitting opportunity to exact vengeance for the outrages perpetrated by the Tarentine rabble. The city, accordingly, came to terms with Pyrrhus. He obtained the supreme command of the troops of the Tarentines and of the other Italians in arms against Rome, along with the right of keeping a garrison in Tarentum. The expenses of the war were, of course, to be borne by the city. Pyrrhus, on the other hand, promised to remain no longer in Italy than was necessary; probably with the tacit reservation that his own judgment should fix the time during which he would be needed there. Nevertheless, the prey had almost slipped out of his hands. While the Tarentine envoys—the chiefs, no doubt, of the war party—were absent in Epirus, the state of feeling in the city, now hard pressed by the Romans, underwent a change. The chief command was already entrusted to Agis, a man favourable to Rome, when the return of the envoys with the concluded treaty, accompanied by Cineas the confidential minister of Pyrrhus, again brought the war party to the helm.

A firmer hand now grasped the reins, and put an end to the pitiful vacillation. In the autumn of 473 [280 BC] Milo, the general of Pyrrhus, landed with 3000 Epirots and occupied the citadel of the town. He was followed in the beginning of the year 474 [279 BC] by the king himself, who landed after a stormy passage in which many lives were lost. He transported to Tarentum a respectable but miscellaneous army, consisting partly of the household troops, Molossians, Thesprotians, Chaonians, and Ambraciots; partly of the Macedonian infantry and the Thessalian cavalry, which Ptolemy king of Macedonia had conformably to stipulation handed over to him; partly of Aetolian, Acarnanian, and Athamanian mercenaries. Altogether it numbered 20,000 Phalangitae, 2000 archers, 500 slingers, 3000 cavalry, and 20 elephants, and thus was not much smaller than the army with which fifty years before Alexander had crossed the Hellespont.