History of the Peloponnesian War

Thereupon the Peloponnesians, wishing to aid the Aeginetans, sent into Aegina three hundred hoplites, who had previously been assisting the Corinthians and Epidaurians. Moreover, the Corinthians occupied the heights of Geraneia, and made a descent upon the territory of M egara in conjunction with their allies, thinking that the Athenians would be unable to aid the Megarians, since many of their troops were away in Aegina and in Egypt, or if they should attempt it that they would have to withdraw from Aegina.

The Athenians, however, did not disturb the army besieging Aegina, but with such forces as were left in the city, consisting of the oldest and the youngest men, marched into Megara, the general in command being Myronides.