The passage of Brasidas was a complete surprise to the people in the town; and the capture of many of those outside, and the flight of the rest within the wall, combined to produce great confusion among the citizens; especially as they did not trust one another. It is even said that if Brasidas, instead of stopping to pillage, had advanced straight against the town, he would probably have taken it. In fact, however, he established himself where he was and overran the country outside, and for the present remained inactive, vainly awaiting a demonstration on the part of his friends within. Meanwhile the party opposed to the traitors proved numerous enough to prevent the gates being immediately thrown open, and in concert with Eucles, the general, who had come from Athens to defend the place, sent to the other commander in Thrace, Thucydides, son of Olorus, the author of this history, who was at the isle of Thasos, a Parian colony, half a day's sail from Amphipolis, to tell him to come to their relief. On receipt of this message he at once set sail with seven ships which he had with him, in order, if possible, to reach Amphipolis in time to prevent its capitulation, or in any case to save Eion.
Meanwhile Brasidas, afraid of succours arriving by sea from Thasos, and learning that Thucydides possessed the right of working the gold mines in that part of Thrace, and had thus great influence with the inhabitants of the continent, hastened to gain the town, if possible, before the people of Amphipolis should be encouraged by his arrival to hope that he could save them by getting together a force of allies from the sea and from Thrace, and so refuse to surrender. He accordingly offered moderate terms, proclaiming that any of the Amphipolitans and Athenians who chose, might continue to enjoy their property with full rights of citizenship; while those who did not wish to stay had five days to depart, taking their property with them.
The bulk of the inhabitants, upon hearing this, began to change their minds, especially as only a small number of the citizens were Athenians, the majority having come from different quarters, and many of the prisoners outside had relations within the walls. They found the proclamation a fair one in comparison of what their fear had suggested; the Athenians being glad to go out, as they thought they ran more risk than the rest, and further, did not expect any speedy relief, and the multitude generally being content at being left in possession of their civic rights, and at such an unexpected reprieve from danger. The partisans of Brasidas now openly advocated this course, seeing that the feeling of the people had changed, and that they no longer gave ear to the Athenian general present; and thus the surrender was made and Brasidas was admitted by them on the terms of his proclamation. In this way they gave up the city, and late in the same day Thucydides and his ships entered the harbour of Eion, Brasidas having just got hold of Amphipolis, and having been within a night of taking Eion: had the ships been less prompt in relieving it, in the morning it would have been his.
After this Thucydides put all in order at Eion to secure it against any present or future attack of Brasidas, and received such as had elected to come there from the interior according to the terms agreed on. Meanwhile Brasidas suddenly sailed with a number of boats down the river to Eion to see if he could not seize the point running out from the wall, and so command the entrance; at the same time he attempted it by land, but was beaten off on both sides and had to content himself with arranging matters at Amphipolis and in the neighbourhood. Myrcinus, an Edonian town, also came over to him; the Edonian king Pittacus having been killed by the sons of Goaxis and his own wife Brauro; and Galepsus and Oesime, which are Thasian colonies, not long after followed its example. Perdiccas too came up immediately after the capture and joined in these arrangements.