The immediate effect, indeed, of this union of the Italian and Sicilian Greeks under one control was a closer concert also on the part of their antagonists. Carthage and Rome now converted their old commercial treaties into an offensive and defensive league against Pyrrhus (475), the tenor of which was that, if Pyrrhus invaded Roman or Carthaginian territory, the party which was not attacked should furnish that which was assailed with a contingent on its own territory and should itself defray the expense of the auxiliary troops; that in such an event Carthage should be bound to furnish transports and to assist the Romans also with a war fleet, but the crews of that fleet should not be obliged to fight for the Romans by land; that lastly, both states should pledge themselves not to conclude a separate peace with Pyrrhus. The object of the Romans in entering into the treaty was to render possible an attack on Tarentum and to cut off Pyrrhus from his own country, neither of which ends could be attained without the co-operation of the Punic fleet; the object of the Carthaginians was to detain the king in Italy, so that they might be able without molestation to carry into effect their designs on Syracuse.(5) It was accordingly the interest of both powers in the first instance to secure the sea between Italy and Sicily. A powerful Carthaginian fleet of 120 sail under the admiral Mago proceeded from Ostia, whither Mago seems to have gone to conclude the treaty, to the Sicilian straits. The Mamertines, who anticipated righteous punishment for their outrage upon the Greek population of Messana in the event of Pyrrhus becoming ruler of Sicily and Italy, attached themselves closely to the Romans and Carthaginians, and secured for them the Sicilian side of the straits. The allies would willingly have brought Rhegium also on the opposite coast under their power; but Rome could not possibly pardon the Campanian garrison, and an attempt of the combined Romans and Carthaginians to gain the city by force of arms miscarried. The Carthaginian fleet sailed thence for Syracuse and blockaded the city by sea, while at the same time a strong Phoenician army began the siege by land (476). It was high time that Pyrrhus should appear at Syracuse: but, in fact, matters in Italy were by no means in such a condition that he and his troops could be dispensed with there. The two consuls of 476, Gaius Fabricius Luscinus, and Quintus Aemilius Papus, both experienced generals, had begun the new campaign with vigour, and although the Romans had hitherto sustained nothing but defeat in this war, it was not they but the victors that were weary of it and longed for peace. Pyrrhus made another attempt to obtain accommodation on tolerable terms. The consul Fabricius had handed over to the king a wretch, who had proposed to poison him on condition of being well paid for it. Not only did the king in token of gratitude release all his Roman prisoners without ransom, but he