Tarentum remained in his hands and thus rendered it possible for him to renew the war at his pleasure, and the Romans could not think of undertaking the siege of that city.  Even apart from the fact that in siege-warfare, which had been revolutionized by Philip of Macedonia and Demetrius Poliorcetes, the Romans were at a very decided disadvantage when matched against an experienced and resolute Greek commandant, a strong fleet was needed for such an enterprise, and, although the Carthaginian treaty promised to the Romans support by sea, the affairs of Carthage herself in Sicily were by no means in such a condition as to enable her to grant that support.

Pyrrhus Master of Sicily

The landing of Pyrrhus on the island, which, in spite of the Carthaginian fleet, had taken place without interruption, had changed at once the aspect of matters there.  He had immediately relieved Syracuse, had in a short time united under his sway all the free Greek cities, and at the head of the Sicilian confederation had wrested from the Carthaginians nearly their whole possessions.  It was with difficulty that the Carthaginians could, by the help of their fleet which at that time ruled the Mediterranean without a rival, maintain themselves in Lilybaeum; it was with difficulty, and amidst constant assaults, that the Mamertines held their ground in Messana.  Under such circumstances, agreeably to the treaty of 475, it would have been the duty of Rome to lend her aid to the Carthaginians in Sicily, far rather than that of Carthage to help the Romans with her fleet to conquer Tarentum; but on the side of neither ally was there much inclination to secure or to extend the power of the other.  Carthage had only offered help to the Romans when the real danger was past; they in their turn had done nothing to prevent the departure of the king from Italy and the fall of the Carthaginian power in Sicily.  Indeed, in open violation of the treaties Carthage had even proposed to the king a separate peace, offering, in return for the undisturbed possession of Lilybaeum, to give up all claim to her other Sicilian possessions and even to place at the disposal of the king money and ships of war, of course with a view to his crossing to Italy and renewing the war against Rome.  It was evident, however, that with the possession of Lilybaeum and the departure of the king the position of the Carthaginians in the island would be nearly the same as it had been before the landing of Pyrrhus; the Greek cities if left to themselves were powerless, and the lost territory would be easily regained.  So Pyrrhus rejected the doubly perfidious proposal, and proceeded to build for himself a war fleet.  Mere ignorance and shortsightedness in after times censured this step; but it was really as necessary as it was, with the resources of the island, easy of accomplishment.  Apart from the consideration that the master of Ambracia, Tarentum, and Syracuse could not dispense with a naval force, he needed a