History of the Peloponnesian War

Now the Argives had from the first been aware of the preparations of the Lacedaemonians; and when they were on their march for the purpose of joining the rest at Phlius, then they also took the field. They were reinforced by the Mantineans with their allies, and by three thousand heavy-armed of the Eleans.

And as they advanced, they met the Lacedaemonians at Methydrium in Arcadia, and each army occupied a hill. The Argives then prepared to engage the Lacedaemonians, cut off as they were by themselves: but Agis broke up in the night, and eluding them, proceeded to the rest of the allies at Phlius.

The Argives, on finding this, marched, as soon as it was morning, to Argos first, and then to where they expected the Lacedaemonians with their allies would descend into their country, namely, the road running by Nemea.

Agis, however, did not take that road, as they expected him to do; but having given orders to the Lacedaemonians, Arcadians, and Epidaurians, he advanced by another and more difficult route, and so came down into the plain of Argos. The Corinthians, Pellenians, and Phliasians marched by another steep road; while the Boeotians, Megareans, and Sicyonians had been ordered to descend by that leading to Nemea, where the Argives were posted, in order that, if the Argives should advance into the plain against his own division, they might hang on their rear, and use their cavalry with effect.

He then, having made these arrangements and entered the plain, proceeded to ravage Saminthus and other places.