It was not till next day that Clearchus and his colleagues learned by messengers from Ariæus that Cyrus was slain, and that Ariæus had fallen back to the last halting-place, where he proposed to wait twenty-four hours, and no more, before starting in his retreat westward. Clearchus replied, that the Greeks, for their part, had been victorious, and that if Ariæus would rejoin them they would win the Persian crown for him, since Cyrus was dead. The next message was from Artaxerxes inviting the Greeks to give up their arms; to which they replied that he might come and take them if he could, but if he meant to treat them as friends, they would be no use to him without their arms, if as enemies, they would keep them to defend themselves. Though no formal appointment was made, the Greeks recognised Clearchus as their leader. They fell back to join Ariæus, who declined the proposal to seat him on the Persian throne; and it was agreed to follow a new route in retreat to Ionia, the way by which the force had advanced being now impracticable. Now, however, Artaxerxes began to negotiate through Tissaphernes, the Greeks maintaining a bold and even contemptuous front, warranted by the king's obvious fear of risking an engagement. Finally, an offer came to conduct the Greeks back to Grecian territory, providing them, at their own cost, with necessaries. Prolonged delays, however, aroused suspicions of treachery among the Greeks, who distrusted Tissaphernes and Ariæus alike; but Clearchus held it better not to break openly with the Persians. The march at last began along a northerly route towards the Black Sea, the Greeks keeping rigidly apart from the Persian forces which accompanied them, in readiness for an attack. At the crossing of the Tigris suspicion was particularly active, the conduct of Ariæus being especially dubious; but still no overt hostilities were attempted until the river Zabatus was reached, after three weeks of marching. Here Clearchus endeavoured to end the extremely strained relations between the Greeks and the barbarian commanders by an interview with Tissaphernes. Both men carefully repudiated any idea of hostile intentions, and the Persian invited Clearchus and the Greek officers generally to attend a conference. Not all, but a considerable number--five generals, including Clearchus, Proxenus, and Menon, with twenty more officers and nearly two hundred others--attended. At a given signal all were treacherously massacred; but a fugitive reached the Greek camp, where the men sprang to arms. Ariæus, approaching with an escort, declared that Clearchus had been proved guilty of treason, but was received with fierce indignation, and withdrew.