History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
The same winter, Brasidas with his allies Thrace-ward marched against Amphipolis, the Athenian colony on the river Strymon.
On the site on which the town now stands a settlement was before attempted by Aristagoras the Milesian, when flying from king Darius; but he was driven away by the Edonians: and then by the Athenians, two-and-thirty years later, who sent ten thousand settlers of their own citizens, and whoever else would go; who were cut off by the Thracians at Drabescus.
Twenty-nine years after, the Athenians went again, Hagnon son of Nicias being sent out as leader of the colony, and expelled the Edonians, and founded a town on the spot which before was called
Nineways.They set out for the purpose from Eion, which they occupied themselves at the mouth of the river, on the coast, at a distance of five-and-twenty stades from the present town, which Hagnon named [*]( i. e. a city looking both ways. For a description of it see the memoir at the end of Arnold' s 2nd volume) Amphipolis, because, as the river Strymon flows round it on both sides, [*]( I have followed Arnold in supposing that διὰ in this passage expresses final, rather than efficient cause. as it often does with an infinitive mood: at least I infer that such was his view of it, from the passages which he compare with it, δι᾽ ἀχθηδόνα, ch. 40. 2. and V. 53. διὰ την ἔσπραξιν) with a view to enclosing it, he ran a long wall across from river to river, and built the town so as to be conspicuous both towards the sea and towards the land.