his disinterested conduct all they asked was
that a Peloponnesian army should be sent into Boeotia for the defence
of the Attic frontier: a request which the Spartan envoys promised to
fulfil. No sooner, however, had they returned into their own country
than this promise was completely forgotten.

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.

Mardonius, on learning the approach of the Lacedaemonians, abandoned
Attica and crossed into Boeotia. He finally took up a position on the
left bank of the Asopus, and not far from the town of Plataea. Here he
caused a camp to be constructed of ten furlongs square, and fortified
with barricades and towers. Meanwhile the Grecian army continued to
receive reinforcements from the different states, and by the time it
reached Boeotia, it formed a grand total of about 110,000 men. After
several days' manoeuvring a general battle took place near Plataea.
The light-