The feeling of discontent with the policy of supporting Sparta against such an opponent now reached its height in the mind of Pharnabazos. He opened communications with Thrasyllos, who had been left to carry on the siege of Chalkedôn while Alkibiades was away strengthening the power of Athens on the Propontis, and collecting tribute for the support of her defenders. He promised an immediate payment of twenty talents, proposed a treaty of peace, and offered an escort and safe-conduct to an Athenian embassy, which he suggested should be sent to the Great King to settle the terms upon which a final peace might be made between Persia and Athens. In the meantime a truce was to be made between the satrap and Alkibiades. The satrap’s terms were accepted and the embassy was sent. It included one whose travels and troubles we have already spoken about—the unfortunate Mantitheos, whose sufferings were now to be continued for three years to come. But Pharnabazos was not content with the word or oath of a subordinate before he withdrew his troops finally from the support of the Spartans. He insisted that the general-in-chief must himself attest his consent to all the terms of the treaty. Alkibiades confirming them by his own solemn oath, the satrap made mutual covenants of friendship, alliance, and hospitality with him, treating him throughout more as an autocratic sovereign than as a general-in-chief of a republic. Having fortified Chrysopolis, the port of Chalkedôn, by building a strong tower which looked across the narrow strait to Byzantion, Alkibiades now set about his long-meditated siege of that important place which was the bulwark of the Bosporus and the key to the Euxine trade. But Byzantion was strongly guarded by stone walls without and by an unrelenting warrior within, the iron-willed and iron-hearted Klearchos, whom Sparta had sent as her best commander to hold a place of such inestimable value. He was supported by a strong body of his trained citizens and sturdy Boiotians. The Athenian fleet blockaded the port and every entrance by sea; the Athenian army gradually drew round it on the land side, and stopped all help from coming to the famine-stricken people of that great city. Klearchos closely hoarded the food he had stored up within. ‘This,’ he said, ‘is wanted by those who can bear arms and fight; the rest, if needs be, can starve.’