When Antigonus with a large force was crossing the mountain-range of Geraneia, Cleomenes thought it more advisable to fortify thoroughly, not the Isthmus, but the Oneian range of hills, and to wear out the Macedonians by a war of posts and positions, rather than to engage in formal battle with their disciplined phalanx. He carried out this plan, and thereby threw Antigonus into straits.
For he had not a sufficient store of provisions, and it was no easy matter to force his passage while Cleomenes sat entrenched. Moreover, when he attempted to slip past his enemy in the night by way of Lechaeum, he was driven out and lost some of his soldiers. Therefore Cleomenes was altogether encouraged, and his men, elated by their victory, betook themselves to supper; but Antigonus was dejected, since he was shut up by necessity to difficult plans.
For he was planning to march off to the promontory of the Heraeum, and from there to put his army across to Sicyon in transports—an undertaking requiring much time and extraordinary preparations. But when it was already towards evening, there came to him from Argos by sea some friends of Aratus, who summoned him to the city, on the ground that the Argives were ready to revolt from Cleomenes. The author of the revolt was Aristotle; and the multitude were easy to persuade, being incensed because Cleomenes had not brought about the abolition of debts which they expected.
Accordingly, Aratus took fifteen hundred soldiers from Antigonus and sailed to Epidaurus. Aristotle, however, did not await his coming, but at the head of the citizens made an attack upon the garrison of the citadel; and Timoxenus came to his aid from Sicyon with the Achaean army.