Thus ended the campaign of 474. The separate peace which at the decisive moment Etruria had concluded with Rome, and the king's unexpected retreat which entirely disappointed the high-strung hopes of the Italian confederates, counterbalanced in great measure the impression of the victory of Heraclea. The Italians complained of the burdens of the war, particularly of the bad discipline of the mercenaries quartered among them, and the king, weary of the petty quarrelling and of the impolitic as well as unmilitary conduct of his allies, began to have a presentiment that the problem which had fallen to him might be, despite all tactical successes, politically insoluble. The arrival of a Roman embassy of three consulars, including Gaius Fabricius the conqueror of Thurii, again revived in him for a moment the hopes of peace; but it soon appeared that they had only power to treat for the ransom or exchange of prisoners. Pyrrhus rejected their demand, but at the festival of the Saturnalia he released all the prisoners on their word of honour. Their keeping of that word, and the repulse by the Roman ambassador of an attempt at bribery, were celebrated by posterity in a manner most unbecoming and betokening rather the dishonourable character of the later, than the honourable feeling of that earlier, epoch.

In the spring of 475 Pyrrhus resumed the offensive, and advanced into Apulia, whither the Roman army marched to meet him. In the hope of shaking the Roman symmachy in these regions by a decisive victory, the king offered battle a second time, and the Romans did not refuse it. The two armies encountered each other near Ausculum (Ascoli di Puglia).  Under the banners of Pyrrhus there fought, besides his Epirot and Macedonian troops, the Italian mercenaries, the burgess-force - the white shields as they were called - of Tarentum, and the allied Lucanians, Bruttians, and Samnites - altogether 70,000 infantry, of whom 16,000 were Greeks and Epirots, more than 8000 cavalry, and nineteen elephants. The Romans were supported on that day by the Latins, Campanians, Volscians, Sabines, Umbrians, Marrucinians, Paelignians, Frentanians, and Arpanians. They too numbered above 70,000 infantry, of whom 20,000 were Roman citizens, and 8000 cavalry. Both parties had made alterations in their military system. Pyrrhus, perceiving with the sharp eye of a soldier the advantages of the Roman manipular organization, had on the wings substituted for the long front of his phalanxes an arrangement by companies with intervals between them in imitation of the cohorts, and - perhaps for political no less than for military reasons - had placed the Tarentine and Samnite cohorts between the subdivisions of his own men. In the centre alone the Epirot phalanx stood in close order. For the purpose of keeping off the elephants the Romans produced a species of war-chariot, from which projected iron poles furnished with chafing-dishes, and on which were fastened moveable masts adjusted with a view to being lowered, and ending in an iron spike - in some degree the model of the boarding-bridges which were to play so great a part in the first Punic war.

According to the Greek account of the battle, which seems less one-sided than the Roman account also extant, the Greeks had the disadvantage on the first day, as they did not succeed in deploying their line along the steep and marshy banks of the river where they were compelled to accept battle, or in bringing their cavalry and elephants into action. On the second day, however, Pyrrhus anticipated the Romans in occupying the intersected ground, and thus gained without loss the plain where he could without disturbance draw up his phalanx.  Vainly did the Romans with desperate courage fall sword in hand on the sarissae; the phalanx preserved an unshaken front under every assault, but in its turn was unable to make any impression on the Roman legions. It was not till the numerous escort of the elephants had, with arrows and stones hurled from slings, dislodged the combatants stationed in the Roman war-chariots and had cut the traces of the horses, and the elephants pressed upon the Roman line, that it began to waver. The giving way of the guard attached to the Roman chariots formed the signal for universal flight, which, however, did not involve the sacrifice of many lives, as the adjoining camp received the fugitives. The Roman account of the battle alone mentions the circumstance, that during the principal engagement an Arpanian corps detached from the Roman main force had attacked and set on fire the weakly-guarded Epirot camp; but, even if this were correct, the Romans are not at all justified in their assertion that the battle remained undecided. Both accounts, on the contrary, agree in stating that the Roman army retreated across the river, and that Pyrrhus remained in possession of the field of battle. The number of the fallen was, according to the Greek account, 6000 on the side of the Romans, 3505 on that of the Greeks[4]. Amongst the wounded was the king himself, whose arm had been pierced with a javelin, while he was fighting, as was his wont, in the thickest of the fray. Pyrrhus had achieved a victory, but his were unfruitful laurels; the victory was creditable to the king as a general and as a soldier, but it did not promote his political designs. What Pyrrhus needed was a brilliant success which should break up the Roman army and give an opportunity and impulse to the wavering allies to change sides; but the Roman army and the Roman confederacy still remained unbroken, and the Greek army, which was nothing without its leader, was fettered for a considerable time in consequence of his wound. He was obliged to renounce the campaign and to go into winter quarters; which the king took up in Tarentum, the Romans on this occasion in Apulia. It was becoming daily more evident that in a military point of view the resources of the king were inferior to those of the Romans, just as, politically, the loose and refractory coalition could not stand a comparison with the firmly-established Roman symmachy.  The sudden and vehement style of the Greek warfare and the genius of the general might perhaps achieve another such victory as those of Heraclea and Ausculum, but every new victory was wearing out his resources for further enterprise, and it was clear that the Romans already felt themselves the stronger, and awaited with a courageous patience final victory.  Such a war as this was not the delicate game of art that was practised and understood by the Greek princes. All strategical combinations were shattered against the full and mighty energy of the national levy. Pyrrhus felt how matters stood: weary of his victories and despising his allies, he only persevered because military honour required him not to leave Italy till he should have secured his clients from barbarian assault. With his impatient temperament it might be presumed that he would embrace the first pretext to get rid of the burdensome duty; and an opportunity of withdrawing from Italy was soon presented to him by the affairs of Sicily.

After the death of Agathocles (465) the Greeks of Sicily were without any leading power. While in the several Hellenic cities incapable demagogues and incapable tyrants were replacing each other, the Carthaginians, the old rulers of the western point, were extending their dominion unmolested. After Agrigentum had surrendered to them, they believed that the time had come for taking final steps towards the end which they had kept in view for centuries, and for reducing the whole island under their authority; they set themselves to attack Syracuse. That city, which formerly by its armies and fleets had disputed the possession of the island with Carthage, had through internal dissension and the weakness of its government fallen so low that it was obliged to seek for safety in the protection of its walls and in foreign aid; and none could afford that aid but king Pyrrhus. Pyrrhus was the husband of Agathocles's daughter, and his son Alexander, then sixteen years of age, was Agathocles's grandson. Both were in every respect natural heirs of the ambitious schemes of the ruler of Syracuse; and if her freedom was at an end, Syracuse might find compensation in becoming the capital of a Hellenic empire of the West. So the Syracusans, like the Tarentines, and under similar conditions, voluntarily offered their sovereignty to king Pyrrhus (about 475); and by a singular conjuncture of affairs everything seemed to concur towards the success of the magnificent plans of the Epirot king, based as they primarily were on the possession of Tarentum and Syracuse.