History of the Peloponnesian War

The Lacedaemonians were [that day] celebrating a certain holiday, and when they heard the news did set lightly by it, conceiving that whensoever it should please them to go thither, they should find them either already gone or easily take the place by force.

Somewhat also they were retarded by reason that their army was in Attica. The Athenians, having in six days finished the wall to the land and in the places where was most need, left Demosthenes with five galleys to defend it and with the rest hastened on in their course for Corcyra and Sicily.