Plutarch, Aratus
Bernadotte Perrin, Ed.

44. At Pegae Antigonus and Aratus exchanged oaths of fidelity, and straightway marched against the enemy at Corinth. And there were conflicts about the city, Cleomenes being well fortified, and the Corinthians defending themselves with ardour. Meanwhile, however, Aristotle the Argive, who was a friend of Aratus, sent secretly to him and promised to bring his city to revolt from Cleomenes if Aratus would come thither with soldiers. [2] So Aratus, after informing Antigonus, took fifteen hundred men and sailed from the Isthmus to Epidaurus with all speed.¹ But the Argives, revolting prematurely, attacked the garrison of Cleomenes and shut them up in the citadel, and Cleomenes, learning of this, and fearing that if his enemies got possession of Argos they would cut him off from a safe return home, abandoned Acrocorinthus while it was still night and went to their aid. [3] He succeeded in getting into Argos first, routing some of the enemy on the way; but shortly afterwards Aratus came up, and Antigonus showed himself with his forces, and Cleomenes therefore retreated to Mantineia. Upon this the cities all came over to the Achaeans again, Acrocorinthus was handed over to Antigonus, and Aratus, having been chosen general by the Argives, persuaded them to make a present to Antigonus of the property of the tyrants and of the traitors. [4] As for Aristomachus, he was tortured at Cenchreae and then thrown into the sea; for which deed, more than any other, Aratus was reproached, on the ground that he had allowed a man to be lawlessly put to death who was not wicked, but had cooperated with him, and at his persuasion had renounced his power and attached his city to the Achaean League.²