History of the Peloponnesian War

The Athenian generals, however, saw that some obstacle had arisen and that they would not be able to take the city by force, and therefore at once began to invest Nisaea with a wall, thinking that, if they could take this town before any succour came, Megara also would soon capitulate.

A supply of iron quickly arrived from Athens, as well as stonemasons and whatever else was needed. Beginning then at the part of the fortification which they already held and building a cross-wall on the side of it facing Megara, from that point they built out on either side of Nisaea as far as the sea, the army apportioning among them the ditch and the walls and using stones and bricks from the suburbs. Moreover, they cut down fruit-trees and forest-wood and built stockades wherever they were needed; and the houses of the suburbs with the addition of battlements of themselves furnished a rampart.

They worked the whole of this first day, but on the next day toward evening when the wall was all but finished the garrison of Nisaea, becoming alarmed by the shortage of food, seeing that they received provisions from the upper-city for only a day at a time, and not anticipating any speedy relief from the Peloponnesians, and believing the Megarians to be hostile, capitulated to the Athenians on condition that they should give up their arms and pay a ransom of a stipulated amount for each man; as for the Lacedaemonians in the garrison, the commander or anyone else, they were to be disposed of as the Athenians might wish. On these terms they came to an agreement and marched out.

The Athenians then made a breach in the long walls in order to separate them from the wall of the city of Megara, took possession of Nisaea, and proceeded with their other preparations.