When Mardonius was informed that the Athenians had rejected his proposal, he immediately marched against Athens, accompanied by all his Grecian allies; and in May or June, B.C. 479, about ten months after the retreat of Xerxes, the Persians again occupied that city. With feelings of bitter indignation against their faithless allies, the Athenians saw themselves once more compelled to remove to Salamis. Mardonius took advantage of his situation to endeavour once more to win them to his alliance. Through a Hellespontine Greek, the same favourable conditions were again offered to them, but were again refused. One voice alone, that of the senator Lycidas, broke the unanimity of the assembly. But his opposition cost him his life. He and his family were stoned to death by the excited populace. In this desperate condition the Athenians sent ambassadors to the Spartans to remonstrate against their breach of faith, and to intimate that necessity might at length compel them to listen to the proposals of the enemy. The Spartans became alarmed. That very night 5000 citizens, each attended by seven Helots, were despatched to the frontiers; and these were shortly followed by 5000 Lacedaemonian Perioeci, each attended by one light-armed Helot. Never before had the Spartans sent so large a force into the field. Their example was followed by other Peloponnesian cities; and the Athenian envoys returned to Salamis with the joyful news that a large army was preparing to march against the enemy, under the command of Pausanias, who acted as regent for the infant son of Leonidas.