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.
They then directed the Mendaeans henceforth to retain their former constitution, and bring to trial among themselves any whom they thought guilty of the revolt; but the men on the acropolis they fenced off with a wall extending on either side down to the sea, and set a guard over them. And when they had thus secured Mende, they proceeded against Scione.
The Scionaeans and the Peloponnesians had come out against them and taken position on a strong hill before the city, which had to be taken by the enemy before the city could be invested with a wall.
So the Athenians made a furious assault upon the hill and dislodged those that were upon it; they then encamped and, after raising a trophy, prepared for the circumvallation.
But not long afterwards, when they were already at work, the auxiliaries who were besieged on the acropolis of Mende forced their way by night along the shore through the guard and reached Scione; and most of them escaped through the besieging army and got into the city.
While the circumvallation of Scione was in progress, Perdiccas sent a herald to the Athenian generals and made an agreement with them; he was moved to this by the hatred he bore Brasidas for his retreat from Lyncus, at which time indeed he had begun his negotiations.[*](cf. 4.128.5.)
Now it happened at that time that Ischagoras, the Lacedaemonian, was on the point of taking an army by land to join Brasidas, but Perdiccas, partly because Nicias urged him, since he had made terms with the Athenians, to give them some token of his sincerity, partly also because he himself no longer wished the Peloponnesians to enter his territory, now worked upon his friends in Thessaly, with the foremost of whom he was always on good terms, and effectually stopped the army and the expedition, to such a degree that they did not even try to obtain permission from the Thessalians.