Plutarch, Aratus
Bernadotte Perrin, Ed.

39. So, then, the Achaeans lost Mantineia, which was taken again by Cleomenes, and after being defeated in a great battle at Hecatombaeum they were so dismayed that they sent at once and invited Cleomenes to come to Argos and assume the leadership. [2] But Aratus, when he learned that Cleomenes was on the way and at Lerna with his forces, feared the issue, and sent an embassy to demand that he should come with three hundred men only, as to friends and allies, and that if he was distrustful, he should accept hostages. Cleomenes declared that he was insulted and mocked by this demand, and retired with his army, after writing a letter to the Achaeans which was full of bitter accusations against Aratus. [3] Aratus also wrote letters against Cleomenes; and their mutual abuse and defamation reached the point of maligning one another's marriages and wives.

As a result of this, Cleomenes sent a herald to declare war against the Achaeans, and almost succeeded in seizing the city of Sicyon with the help of traitors; he turned aside, however, when close at hand, and assaulted and took the city of Pellene, from which the Achaean commander fled. And not long afterwards he took Pheneus also and Penteleium. [4] Then Argos went over to his side, and Phlius received a garrison which he sent. In a word, not one of their acquisitions longer held firm to the Achaeans, but a vast confusion suddenly encompassed Aratus. He saw Peloponnesus shaking, and its cities everywhere stirred to revolt by restless agitators.¹