History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
Myrcinus also, an Edonian town, came over to him, Pittacus, the king of the Edonians, having been killed by the sons of Goaxis and his own wife Brauro; and not long afterwards Galepsus and Oesyme, colonies of the Thasians, also came over. Perdiccas,[*](Now evidently reconciled with Brasidas, with whom he had quarrelled (4.86.3); cf. 4.103.3.) too, came to Amphipolis directly after its capture and joined in arranging these matters.
The Athenians were greatly alarmed by the capture of Amphipolis. The chief reason was that the city was useful to them for the importation of timber for ship-building and for the revenue it produced, and also that, whereas hitherto the Lacedaemonians had possessed, under the guidance of the Thessalians, access to the Athenian allies as far as the Strymon, yet as long as they did not control the bridge—the river for a long way above the town being a great lake and triremes being on guard in the direction of Eion—they could not have advanced further; but now at last the matter had become easy.[*](Or, retaining ῥᾳδία of the MSS and the Vulgate reading ἐνομὶζετο, “but now the access was thought to have become easy.”) And they feared, too, the revolt of their allies.