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.
After the Lacedaemonians had thus spoken, they were, on the advice of Themistocles, immediately dismissed by the Athenians, with the answer that ambassadors should be sent to Sparta to discuss the question.
Themistocles told the Athenians to send him off with all speed to Lacedaemon, but not to despatch his colleagues as soon as they had selected them, but to wait until they had raised their wall to the height from which defence was possible.
Meanwhile the whole population in the city was to labour at the wall, the Athenians, their wives and their children, sparing no edifice, private or public, which might be of any use to the work, but throwing all down.
After giving these instructions, and adding that he would be responsible for all other matters there, he departed.
Arrived at Lacedaemon he did not seek an audience with the authorities, but tried to gain time and made excuses.
When any of the government asked him why he did not appear in the assembly, he would say that he was waiting for his colleagues, who had been detained in Athens by some engagement; however, that he expected their speedy arrival, and wondered that they were not yet there.