History of the Peloponnesian War

The Athenian generals, finding that some obstacle had arisen, and that they would not be able to take the city by force, immediately proceeded to invest Nisaea; thinking that if they could take it before it was relieved, Megara also would the more quickly surrender.

Now iron, stone-masons. and all other requisites were quickly brought from Athens. So they began from the wall which they occupied, and built a cross-wall on the side of Megara, from the point mentioned down to the sea on each side of Nisaea; the whole army having divided amongst themselves the trench and walls; and they used the stones and bricks from the suburb, and cutting down the fruit trees and timber, strengthened with a palisade whatever point might require it. The houses, too, in the suburb, when provided with battlements, were in themselves a fortification. That whole day they continued working;

and about afternoon of the next day the wall was all but completed, when the garrison in Nisaea, in despair of provisions, (for they used to receive daily rations from the upper city,) not thinking that the Peloponnesians would soon relieve them, and supposing the Megareans to be their enemies, capitulated to the Athenians, on condition that after surrendering their arms they should each be ransomed for a stipulated sum; but that the Lacedaemonians, both the commander and all others in the place, should be treated by the Athenians according to their pleasure. On these conditions they surrendered and went out;

and the Athenians, having broken down the long walls at their abutment on Megara, and having taken possession of Nisaea, proceeded with their other preparations.

Now Brasidas son of Tellis, the Lacedaemonian, happened at this time to be in the neighbourhood of Sicyon and Corinth, preparing an army for Thrace. And when he heard of the capture of the walls, fearing both for the Peloponnesians in Nisaea, and lest Megara should be taken, he sent to the Boeotians with orders to meet him with a body of troops as quickly as possible at Tripodiscus, (it is a village in the Megarean territory that has this name, under Mount Gerania,) and went himself with two thousand seven hundred Corinthian heavy-armed, four hundred Phliasian, six hundred Sicyonian, and all his own forces that had been already raised, thinking that he should still find Nisaea untaken.

But when he heard of its capture, (for he happened to have gone out to Tripodiscus by night,) picking out three hundred men from his army, before he was heard of, he advanced to Megara unobserved by the Athenians, who were about the shore; wishing nominally, and really too, if he could, to make an attempt on Nisaea; but, above all, to effect an entrance into Megara, and secure it. Accordingly he begged them to receive his forces, telling them that he was in hope of recovering Nisaea.