History of the Peloponnesian War

In the mean time the commons at Argos were afraid of the Lacedaemonians, and as they courted the alliance of Athens again, and thought it would be of the greatest service to them, they built long walls to the sea; that if they should be excluded from the use of the land, the importation of things by sea, through the help of the Athenians, might be of benefit to them.

Some of the cities in the Peloponnese were also privy to their building these walls. The Argives therefore were engaged in the work with all their population, themselves, their wives, and their slaves; while there came to them from Athens carpenters and stone-masons. And so the summer ended.

The following winter, when the Lacedaemonians were aware of their building the walls, they marched against Argos, both themselves and their allies, excepting the Corinthians; communication being also held with them from Argos itself. The leader of the army was Agis, son of Archidamus, king of the Lacedaemonians.