History of the Peloponnesian War

The news that Amphipolis was in the hands of the enemy caused great alarm at Athens. Not only was the town valuable for the timber it afforded for shipbuilding, and the money that it brought in; but also, although the escort of the Thessalians gave the Lacedaemonians a means of reaching the allies of Athens as far as the Strymon, yet as long as they were not masters of the bridge but were watched on the side of Eion by the Athenian galleys, and on the land side impeded by a large and extensive lake formed by the waters of the river, it was impossible for them to go any further. Now, on the contrary, the path seemed open. There was also the fear of the allies revolting,

owing to the moderation displayed by Brasidas in all his conduct, and to the declarations which he was everywhere making that he was sent out to free Hellas.

The towns subject to the Athenians, hearing of the capture of Amphipolis and of the terms accorded to it, and of the gentleness of Brasidas, felt most strongly encouraged to change their condition, and sent secret messages to him, begging him to come on to them; each wishing to be the first to revolt.