History of the Peloponnesian War

The Lacedaemonians voted that the treaty had been broken, and that war must be declared, not so much because they were persuaded by the arguments of the allies, as because they feared the growth of the power of the Athenians, seeing most of Hellas already subject to them.

The way in which Athens came to be placed in the circumstances under which her power grew was this.

After the Medes had returned from Europe, defeated by sea and land by the Hellenes, and after those of them who had fled with their ships to Mycale had been destroyed, Leotychides, King of the Lacedaemonians, the commander of the Hellenes at Mycale, departed home with the allies from Peloponnese. But the Athenians and the allies from Ionia and Hellespont, who had now revolted from the king, remained and laid siege to Sestos, which was still held by the Medes. After wintering before it, they became masters of the place on its evacuation by the barbarians; and after this they sailed away from Hellespont to their respective cities.

Meanwhile the Athenian people, after the departure of the barbarian from their country, at once proceeded to carry over their children and wives, and such property as they had left, from the places where they had deposited them, and prepared to rebuild their city and their walls. For only isolated portions of the circumference had been left standing, and most of the houses were in ruins; though a few remained, in which the Persian grandees had taken up their quarters.

Perceiving what they were going to do, the Lacedaemonians sent an embassy to Athens. They would have themselves preferred to see neither her nor any other city in possession of a wall; though here they acted principally at the instigation of their allies, who were alarmed at the strength of her newly acquired navy, and the valor which she had displayed in the war with the Medes.

They begged her not only to abstain from building walls for herself, but also to join them in throwing down the walls that still held together of the ultra-Peloponnesian cities. The real meaning of their advice, the suspicion that it contained against the Athenians, was not proclaimed; it was urged that so the barbarian, in the event of a third invasion, would not have any strong place, such as he now had in Thebes, for his base of operations; and that Peloponnese would suffice for all as a base both for retreat and offence.