History of the Peloponnesian War

Now the Lacedaemonians voted that the treaty had been broken, and that war should be declared, not so much because they were convinced by the arguments of the allies, as because they were afraid that the Athenians might attain to greater power, seeing that most parts of Greece were already under their hands.

For it was in the following manner that the Athenians were brought to those circumstances under which they increased their power.

When the Medes had retreated from Europe after being conquered both by sea and land by the Greeks, and those of them had been destroyed who had fled with their ships to Mycale; Leotychides, king of the Lacedaemonians, who was the leader of the Greeks at Mycale, returned home with the allies that were from the Peloponnese; while the Athenians, and the allies from Ionia and the Hellespont, who had now revolted from the king, stayed behind, and laid siege to Sestos, of which the Medes were in possession. Having spent the winter before it, they took it, after the barbarians had evacuated it; and then sailed away from the Hellespont, each to his own city.

And the people of Athens, when they found the barbarians had departed from their country, proceeded immediately to carry over their children and wives, and the remnant of their furniture, from were they had put them out of the way; and were preparing to rebuild their city and their walls. For short spaces of the enclosure were standing; and though the majority of the houses had fallen, a few remained; in which the grandees of the Persians had themselves taken up their quarters.

The Lacedaemonians, perceiving what they were about to do, sent an embassy [to them]; partly because they themselves would have been more pleased to see neither them nor any one else in possession of a wall; but still more because the allies instigated them, and were afraid of their numerous fleet, which before they had not had, and of the bravery they had shown in the Median war.

And they begged them not to build their walls, but rather to join them in throwing down those of the cities out of the Peloponnese; not betraying their real wishes, and their suspicious feelings towards the Athenians; but representing that the barbarian, if he should again come against them, would not then be able to make his advances from any strong hold, as in the present instance he had done from Thebes; and the Peloponnese, they said, was sufficient for all, as a place to retreat into and sally forth from.